With the history of Glenn and Don H bashing in the internet - including Don Felder's own Facebook page - Don F should know by now that there's the possibility that he's encouraging his fans to bash them even more if he doesn't choose his words more carefully. That's what, I think, is the problem with some people. It's what bothers me, but I can't speak for others.
Like Sodascouts said in her latest post, if Don F had written something like "I can understand why I wasn't invited..." it would be a different matter. But the way he put it is bound to make people "fight for him" so to speak. And it worked. I'm not talking about you, but his fans on his Facebook page.
EDIT:
I would assume that it hurts Don F to see people constantly bashing Don H and Glenn on his Facebook page - especially since Glenn's departure.