Yeah, he pushed back hard against the Python 3 migration, by picking on a small number of trade-offs that he personally didn't like and using that to conclude that the entire endeavour was doomed. The Python 3 migration wasn't flawless by any means, but it was better than he made out.

I know his "criticism" also held back many from moving their libraries to Python 3 by sowing doubt in the community, and ultimately may have slowed down adoption overall.