I spent a lot of time reading about this... TLDR: Basecamp had a list of funny names which originated a long time ago. You can imagine that certain ethnicities have names which sound funnier than a common name, so these names go on the list. Some people think its racist, others don't. These people who don't think its racist still admit its rude/ unprofessional though, just not racist.
Anyway, there was too much political arguing going on in the company, and the founders offered people they can get paid a few months salary to leave, and some people are taking them up on this offer. "About one-third".