Earlier quoted context omitted.
And he had a condescending tone from the beginning (as he always does). Maybe if he was more respectful / likable, the developers would have responded better.
Where? He started completely neutral here: https://github.com/microsoft/terminal/issues/10362 We live in a time where every competent developer is slandered in public if he isn't fully submissive to the great corporate powers.
He's been like this for years, and that's fine when you are hanging out with you buddies over a beer, but now Casey is a public figure.
Being a public figure means you are not 'every competent developer'. The reason this was made so public wasn't ms employees, it was Casey's followers.
The sequence of events he started here ended with his fans and friends on discord feeling justified (because Casey, not them, was right on a technical level) brigading volunteers and microsoft employees alike until at least one of them quit open source.
A truly ugly conclusion that could have been avoided with a more circumspect approach.