A couple of people are unhappy, out of a workforce of 100000. So what?
It also mostly seems to be political reasons. I would imagine a lot of people working for Google just want to do a good job for a good salary, not make Google a vehicle for their political opinions.
I think people pushing their political agenda within a company tend to harm the company and it should therefore be ok to fire them.
That said, I haven't wanted to work for Google for years. But I am from the opposite side from these veterans. I felt it was very unjust when James Damore was fired, and I really don't want to work at a place that distrusts its workers so much that it forces them to go through diversity trainings and things like that. I would feel "unsafe" at Google.