Real talk:
This place's sole reason for existing isn't baseball talk. Quite honestly, there are better places to discuss some of the finer points of the game (The Book blog etc) but they can be pretty dry. Humour has always been a large part of this board's appeal to me and I'm guessing others would echo that sentiment.
Banning legitimate posters for an obvious, inoffensive joke seems like a pretty misguided improvement strategy.