Because what you say is not simply generic "procrastination", but the way you see things, "is" or "is not". It boils down to reproduction, like an artist who makes a portrait, at one point it looks good, but then after several extra strokes it's still good, although different. Which one *is* the (good) one, this is the question? Dynamic types, in my observations, have not this problem, for them everything is "prepare it until it's *satisfactory*", things are not "yes" or "no". Statics can't understand the fluid evolution and cheangeability of things so easily, that things are not a certain way - or at least they don't focus on these, but absolutes.
For the record: based on my observations, Dynamic types are incapable to evaluate themselves, more precisely to put themselves in a box, and ask (more or less directly) the opinion of people on their worthiness, and of course, Statics can't wait to picture everything/everyone. "Am I good?", "am I a loser?" - "all I know is what I can and can't do, but I can't deduce from it where I 'fit'". No matter how capable and how much self-esteem a Dynamic type person has, he/she always in doubt about *what* he is, apart for the sum of his actions, feelings, ideas, etc. A weakness in seeing properties and relations - the blueprints.
But this gives them advantage in getting the job done. They do it until it looks fine, it's all a matter of refinement.
Statics focus on judging what others *are*, Dynamics what others *do*.
---
But you're apparently in search of external boundaries, too - not sure about this - so I could narrow it down to Ti. It's like the difference between playing the violin and the guitar. How can you know when you play the correct note on the violin while you have no reference in support? Of course, it sounds good, but it just doesn't feel "right". The difference between Ti and Fi types stands in the fact that Fi types can subjectively decide what's "good" because they can easily use convenience.
Talking about instruments, I always had this problem, how to tune the guitar? It can be tuned lower or higher, but I end-up using standard E4 - similar to what you say, all (reasons) or none. I have friends who play and they have no existential problem in under-tuning it, but I have this problem because I simply can't find a principle for choosing, if I tune it one tone under and decide it's "perfect", then someone lowers the pitch again without my knowledge, I'll probably like that too! WTF? What should I choose, a multiple of the average frequency of my heart, a divisor of the minimum frequency of the chromatic spectrum? Things like these
.