Normally,I would disagree with this suggestion.
I generally don't like setting limits in discussion topics since we have rules that if followed would keep those threads clean.But it seems that most members can't keep those rules and they tend to be more aggressive towards religious issues.
Also if someone wants to make a thread like that he will find a indirect way to do it,or spam his opinion on other unrelated threads (seen it happen so many times).
The best solution for me would be to increase the members of the staff so that they could follow and clean,not only this threads but all threads and stop deleting them as the fastest and easiest solution and throwing away good things because someone decided to act inappropriate on a thread.However,I understand that finding new staff, which will actually do his job, is hard and takes time so for the moment,banning them will be a good solution.
I strongly disagree with the "if you don't like them move on".If that was the solution then character bashing,self advertisement and other threads would be ok to exist,cause if someone wouldn't like them he could just move on.Same with all rules.Someone is bashing another member?You don't like,move on.But things won't work out good this way.