ZD
“It started with a bang and seems to have fizzled. I dont know why or the specifics, ”
It is because most chassidim dont view Modern orthodox as a lighter form of Judaism, they are raised to believe it is all or nothing.
So if a chassid is going to throw away his upbringing, ie go to college, what is the point in still keeping some restrictions, he isnt going to be Religous anyway, (since he is going to college, maybe not wearing a shtreimel) he may as well go all the way.
It would eb like asking a OTD from the Yeshivish community “why arent you at least reform?”
OF course not all feel this way, but many if not most do.