Oof ... to call other people's decades of research into directed machine learning "a colossal waste of researcher's time" is indeed a rather toxic point of view unsurprisingly causing a bitter reaction in scientists/researchers.

Even if his broader point might be valid (about the most fruitful directions in ML), calling something a "bitter lesson" while insulting a whole field of science is ... something.

Also as someone involved in early RL, he should know better.