I don't think anyone is defending the culture, just saying that this letter is not about workplace conditions and is not protected, no matter how much you wish it was.
His tweets are official company communications. They are every bit as relevant to workplace conditions as would be owning a cat or dog inside your office.
I think many here are getting sick of workplace activism and the self-involved crowd pushing it. I didn't become an engineer to deal with their bullshit. I just wanna work on interesting problems. If I'm unhappy I'll switch teams or get another job.
There is an increasingly troublesome number of people entering the industry who simply don't enjoy working hard. I think every company would do better to fire them.
Sure sounds like a discussion about workplace policies and enforcement to me.