> I genuinely do wonder why that has been the trajectory.

The simple answer here is still likely the best one: Smalltalk and Lisp Machine systems were expensive and proprietary right at the same time that Unix and C became free (and therefore ran everywhere)

Yes, and porting them on top of UNIX wasn't the same thing, while still being commercial.

Even with commercial UNIXes, it was extra on top of standard UNIX developer SKU.

Same with Ada, by the way.