Welcome to the people who want to participate in serious discussions. You still have threads, and whole subreddits for that matter, with jokes. But before this tag, people who wanted a joke-free discussion were unable to do so on Reddit, and had to dig through piles of puns and jokes to get some thoughtful comments. Now we have space for both groups.

Actually it would make more sense to have tags and filters, so you could prioritize the type of comments you want to see.

I'm too young to have known it but I think slashdot had a system like that?