I agree with your entire post. Even though schooling is not designed the same way in my country it still isn't designed for P's. You are rewarded for scrupulousness and studying on a daily basis. Although the number of droputs is not bigger for P's or J's in my area, but there is interesting thing about it. P dropouts are the ones who didn't care for school, usually hoping for art/music etc future or just drinking too much, while J's dropouts are those who didn't care for school, because they already work for some funny money somewhere and already start making families one way or another.
ESTP's are realistic but i'd say just to some degree. Or in other words : our idea of realism, based on common sense and combination of Se-Ti is not the same realism as J's which is based more on social proof and overall knowagle and opinions of society.
For example ESTJ wouldn't jump into business that has never been done before and he can't be sure of the outcome. Meanwhile ENTP wouldn't hesitate and just jump into it no matter what, believing he can be milionaire in a month. ESTP will likely go into it if it seems reasonable and profitable for him - doesn't need proof of others, but also doesn't blindly believe in magic of dreams as N's do.
But for this ESTJ ESTP is still unrealistic.