I enjoy the inapropriate names. The first time I saw ROHYPNOL and RUFFIES galloping about naked on their brave steeds, I couldn't help but laugh.
I do recal seeing somebody with rape in their name. I can't remember the exact name though, and it bugs me. Anyway, that also made me laugh.
I'm not going to try to rationalize away the inapropriatness of using names that include words such as rape, cum, fuck, shit, piss and/or date-rape drugs. They are being used for humorous, immature purposes, and I like it, being a humorous and immature person. I agree with OP, however, that if it specifically says not to use inapropriate names in the rules, then those rules should be followed and enforced. I do not propose that people be summarily (probably used that word wrong) banned/kicked for it, but warnings should be issued and magenta text displayed without remorse.
It should be up to individual server owners. I need to poop.