>I'd be pissed if someone copied my original work 
> or my cat,

That's what the copyright holders of the studios 
felt when they saw your fan cels. What you've 
done and still doing is hurting the others. The 
copyright holders didn't sue you so far, doesn't 
mean they allow you to do such thing. They think 
it's the issue of self-discipline of fans, bot 
you got the right to earn money from selling fan 
cels of their work!

OK, let's take this into another way...
You think it's ok to make fan cels of there work, 
then why can't we make copies of  your stuffs 
also? As you said, as far as you don't sue me, I 
can make tons of those copies to earn money. And 
I'm sure you can't sue me as I had no interest to 
make copies of your work. I like self-creation 
rather than copying.