It's funny that people blame the site for this.

That toxicity is just part of software engineering culture. It's everywhere.

Its karma farming. Number must go up regardless of the human cost. Thats why the same problem is seen here, to a lesser extent.

Karma in social media is a technology to produce competitiveness and unhappiness, usually to increase advertising engagement.

Compare how nice the people are on 4chan /g/ board compared to the declining years of SO. Or Reddit for that matter.