I personally thought it was racist. Nonetheless, the show was going to lose viewers regardless. If Barr stuck around, there would be massive criticism towards ABC as keeping her around would be treated as a sign of consent for her behavior.
Barr = Less viewership
No Barr = Less viewership
ABC should have just canceled the show and look to put out quality entertainment; Something sorely missing from cable TV (Only show I watch now is South Park).
southpark remains epic despite intentionally trying to insult everyone. They never decided to get on the PC train. Perhaps that is part of their recipe to success.
I want you to think about this though. Southpark is able to be edgy because they are known. If a NEW show came out now like Southpark, no one would take it on (as a network).