The reporting tool is useless if the people responsible simply don't respond. I had a similar case a few days ago where one of our users posted SPAM under my comments of other developers and despite asking twice, there was no response. The user has still not been deleted and his email address has not been blocked, so he can continue to cause trouble. His posts are still there and he can probably still see all the activity on new posts in my dashboard. Is this in the interests of the developers and the fan community? I don't think so!
While my issue is resolved and personally I would hate to bother bumping this thread, I do think you raised a valid concern.
From what I had noticed the user I had an issue with (Probably not the same one you dealt with per say) tried to make an alternate account a few months back. For the most part I did ignore him and just reported him to the mods but what did bamboozle me is how the hell he managed to get away with being able to do so under the same username.
Personally in hindsight I realize there is some importance to ignoring some people but even then, the fact that people are allowed to do this is problematic. Then again I haven't really been on here too frequently compared to some other communities I frequently go to just because the whole incident did raise more concerns than nothing else and it makes me hesitant to really be on here when I got shit to do.
I'm not sure both your concern and mine come down to a staffing issue, because I did have to make multiple reports in my situation but needless to say sometimes you really have to pester the mods... which realistically you shouldn't have to do that.