I don’t think it’s demographic changes as much as it is fear of displacement.
Until 2 years ago, software engineering appeared to be an ideal career: strong demand for talent combined with high salaries. But with the productivity gains promised (and often achieved) with coding agents, people are understandably afraid. And people who are afraid take defensive measures: denial, anger, excessive criticism, etc. AI becomes, in some sense, “the enemy.”
I think that better explains the shift in overall tone.