The great thing about NSDOJO and NS tinychat is that they aren't part of the actual NS site, and therefore require a little bit of extra work to access. That extra work weeds out the trolls, because most trolls are way too lazy to post shit if it requires any effort. Toward the end of the original NS chat, that thing was worse than NSG on a boring day in August.
I doubt an NS chat in the main part of the site would ever be as successful as NSDOJO or NS tinychat.