When they fired the guy who invented Javascript because he believes, as I do, that marriage should be between a man and a woman... yes, that was the straw that broke the camels back.
But they were involved in that Gnome Outreach Program for Women fiasco too, if you need another example, and some if not all of the SJW's who were responsible for wasting all of Gnome's resources now work at Mozilla in positions of authority.
You're welcome to try to make a case for their values being superior to mine if you like, but you'd have to be willfully blind to not know that this is happening.