Remember...
You're supposed to expect a younger age group to join this site, it's a Nintendo site after all. You were once a kid too and even though these guys aren't at our maturity level, let them enjoy themselves too.
Solution...
Just join in the fun and if you can't, just ignore the thread and move onto the ones you like. If you're seeing a decline in good quality threads, make some yourself! The staff have set a border line to what is and what isn't acceptable, just report the members who troll to help the mods out and make sure justice is served.
I know where you're coming from though.