i think i've settled more finally on who i think left rey on jakku. i vote for luke despite thoughts i had to the contrary earlier. changed to her family
the main issue i had with luke leaving her there was it seemed to be a very bad place to leave someone you intend to survive. however, he didn't leave her alone but with unkar plutt, the junk dealer (also seemingly a bad choice). plutt is *too* terrible of a choice. it makes no sense. luke couldn't have left her there.
this idea is based on my deciding that luke was taking liberties in people's minds using his force powers which he had at least 15 years to develop even further (probably more). not only did he block certain knowledge or the tendency to be motivated to acquire certain knowledge in rey's mind, but he messed with unkar's head too. i'm sure unkar is one of the "weak minded" so it was probably quite easy for luke. it also probably had a greater chance of sticking since unkar is kind of petty and probably not very self-reflective. unkar was tasked with looking out for rey and possibly ensuring that she developed certain skills. she was not to be sold into slavery or prostitution; or to be harmed. unkar was also never to know any of this consciously enough to ever share it (and since he's a big nobody, known for being kind of a jerk, no one would even suspect him nurturing a surviving child with force powers). jakku is also a planet of no importance. i would prefer luke doesn't even have these abilities. it would be cool if it was one of kylo's unique talents. this could make luke want someone more like rey to fight kylo because with her ability to tap into either side of the force, she can very effectively challenge these dark side abilities. she may even have some effectiveness against snoke if her character is magical enough. and since it's already so magical i see no reason to stop with her previous miracles!
it actually seems fitting that luke would want to block tendencies to leave jakku because he remembers his own journey. from a young age he longed to get the hell off tatooine, join the rebellion, do something great, so on... he doesn't want rey to do that too soon because it would send her off jakku right into danger and there would be no one to save her. she is only to leave when the time is right... (it is oh so mysterious) also, had it not been for his uncle and aunt trying to stop him from leaving all the time, luke would have left tatooine earlier. so now luke recognizes the importance in having some figure like this in keeping a still young and vulnerable future jedi safe. rey apparently doesn't have her own obi-wan on jakku to aid her though (she must aid herself; luke did the best he could in short time maybe). nah.
the reason why it can't be kylo that left her on jakku: 1) i am skeptical that kylo would have been able to mess with rey's memories so effectively. i don't think he would have had the skill yet (he may not even have the skill now). he would have had to mess with unkar's mind too, at the very least to obscure any memory of himself. 2) i've decided that the image of the island rey sees in her mind may have been put there ahead of time by luke. we can't have her actively using the force to contact luke on the island because then she would have been "awakened" and would be detectable by creatures like snoke. luke is watching her; but she cannot see luke (i take back my earlier thoughts to the contrary). he left her the island image as inspiration to later find him (if not as more of a guide). it could even maybe help explain why kylo later thinks he can extract luke's location from her mind when she couldn't have possibly memorized the entire piece of that map (unless she can... everything is so magical after all). oh, and most importantly, it seems luke left the map on jakku for rey to find: two leads so that she'll eventually find her way to him. i think that old guy in the beginning had been traveling a long time and managed to find the map on jakku? 3) if it had been kylo i would think she might have remembered him during the flashbacks better since she's managed to remember little bits of how he destroyed the school, and of him coming towards her? luke is the one she can't identify--he has been obscured from her mind. she knows him as only a myth and even in the flashback just sees him hidden and hooded with r2 (he doesn't interact with her but is more distant). granted, she can't see kylo's face either... so this isn't the best argument. it doesn't matter. the point is, i don't think he did.
i think that kylo may have just left her at the school after he and the others destroyed it and killed everyone, knowing luke would find her anyway. it wouldn't be a stretch for him to assume luke hid her somewhere either. the one issue with this is that it leaves the door open for the jedi to gain a foothold again; more so than abandoning rey in the middle of nowhere himself would. but i think that kylo has a pattern of going with his personal and emotionally-driven motivations over what would be the better plan for the bad guys. we can also use his age to explain irrational decisions, in addition to his recent "turn to the dark side" (a time of instability).
the reason why it isn't her family that left her: if luke messed with her mind anyway, he can leave her with the impression that her family left her and is coming back quite easily (she must wait for them). considering i consider much of her force vision to be flashbacks, i'm not sure she even remembered the day she was left clearly (if it comes as a revelation to her in the vision).
i think it's likely her family was killed around the same time luke's school was destroyed, so i don't think they would have been there to hide her somewhere. even if they were still alive, it would be safe to assume they are on a hit list and are the first place anyone would look to find rey (luke will not know if anyone will be looking necessarily, but it's best not to take any chances) i also don't think luke would have left the task to anyone but himself (he needs to know where she is, and make sure the parameters are set up right). he also needs to make sure she is safe and can do so by manipulating unkar plutt's mind. just no. her family *did* leaver her on jakku. that's what she remembers. this is really probably quite simple.
*if* luke did all of this i'm rather enthralled because of how rapey all of it is in theme. there is already virginal rey, all in creme colors, who goes through "awakening" in steps. early in life, she is deprived of knowledge (and thus of feminine power) by a masculine figure and doesn't really begin to get it back until she encounters a wise feminine grandmotherly figure and opens a pandora's box. soon after, she is abducted in the forest by another masculine figure and then forcibly mind raped. this is the end of her awakening, when not only has she recovered access to the knowledge denied her (also through a psychic rape) but to her power (through violation & what she learns from it). in the second movie, she can't be so virginal anymore. once she recovers all the lost knowledge, it could give cause for fury. yes, well, he didn't do it. it would be ridiculous to add luke to rey's mind rapists. i'm sure the film makers would see the underlying implications and *not* do that.
notes on unkar plutt:
i've scanned through the "novelization" and discovered that unkar plutt is a nastier person than i thought... apparently unkar followed her to 'takodana,' enraged at her for stealing the falcon, and made some threats (how he'd make her and bb-8 pay and it sounded quite sadistic and he has some kind of gross 'thing' for her to boot). he was violent enough about it for chewy to see fit to rip one of his arms off (one should always trust chewy's instincts about a person's character... he is like the family dog). anyway, if unkar is this punishing, he is not safe. he could be a child molester for all we know. he's hideous.
*i'm seriously going back to the idea that her family actually did abandon her there (because they are idiots?). of all the worlds, and all the people, why this jackass? seriously.*