/sp/ came way late in 4chans life. Didn't really have to deal with the blatant pedofuckery that 8chan has. Shit, I think /sp/ was even created on 4chan after jailbait was bannable on /b/. Either way, it was pretty good at keeping people at bay. I think we are at a comfortable place with them, as long as we don't get to masterchan tier.
tbh, the biggest problem is furfags and ponefuckers.
>8chan was because of all the fringe stuff
:^) /sp/ is fringe tho anon.