I used to think this too but having experienced long-term relationships with an ILI sp/sx and SLE sp/sx in the past I realized they never allowed me to get as close as I wanted. I felt the SLE especially could just leave and not come back but he allowed me to get closer to him than the ILI did. When the SLE and I would break up it was always me going after him and getting things back on track, bringing him back home. *sigh* The ILI and I never had a real breakup(until the last one) other than middle of the night fights that led to us making up before the morning. They often put their self interests first and I could not understand why.
I had no benefit of socionics types and stackings information then. I just remember feeling like I would never reach the level of intimacy that I was looking for. It was me not them. I will liken it to trying to squeeze blood from a stone. Having information (even if it is flawed) on what drives humans has been truly enlightening for me and helps me to let go of expectations I have of people. Sometimes they even end up surprising me. SX expectations of intimacy can be over the top and when they try to force it they alienate those who just aren't wired that way.
I do believe I have some tools now that makes it easier for me to see things from the other's perspective. Sometimes love is worth every effort, even if it means I have to balance myself out and reign in my base instinct. The saga continues...