it's nothing personal
I don't know the actors, events, etc, etc, but assuming it is what it looks like I'd say: integrity is always a personal issue and firing someone for cause where there is, in light of fact, no cause is both personal and despicable. Saying it's "just business" doesn't justify unethical business practices. It's horrifying that we've come to associate business with amorality.
You have good perspective. It might take awhile but I am betting you'll land in a better situation. I know how humiliating searching for a job can feel even when you're doing it willingly. While you're looking, remember that job hunting is quite a bit like dating. You're both looking for a good match and a fun, positive, self-confident attitude is very attractive to pretty much everyone.
Total sidebar: you have some chops with the paints. I was a merciless art critic in a former incarnation too so I'm not just saying that. Keep it up! Dig deep while you've got extra cycles and see where it takes you.