I deleted my Reddit account after a short time because I couldn't deal with the level of stupidity on Reddit, though this had nothing to do with pedophilia.
What I wonder is if simply discussing pedophilia would constitute "encouraging" or "promoting" pedophilia. I wouldn't call discussing and defending it the same as encouraging/promoting it. Also I think they're probably being stupid and mean this as encouraging/promoting sex.
You could always use Tor, make an account using a throwaway email address, start posting and see what happens. Waste of time with those pig-headed fools if you ask me, though.