It's not a particularly great question, but it's getting upvotes because people generally have a sense of humor. The most popular answer is humorous but at the expense of a particular subset of cyclist that the rest of the population tends to poke fun at. Not saying this is appropriate or acceptable behavior, just answering your question...
The site, and particularly site moderation, only works if users make a reasonable effort on their own to police behavior. In this particular case, no one as voted to close the question for any reason (like "primarily opinion based") nor has anyone flagged any of the answers or comments.
If, in the future, you see problem questions or answers your best bet is to use the "vote to close" and "flag for moderator attention" buttons.