This is something that I really disagree with in our modern discourse, that people or groups of people are apparently incapable of change.

Mozilla did a thing, Mozilla got crap for it, Mozilla undid the thing and apologized. How does continuing to be publicly mad at them and ending one's use of their product inspire future people or groups to actually change?

It's the same as when people dig through old social media posts and then slag on someone in the here and now for it. "Oh, so you say you are a supporter of [thing] but what about that time in 2005 when you made an off-color joke about [thing] and left it laying around the Wayback Machine for anyone to find with barely an hour's worth of digging?!"