I think that self-closing a debate is okay if you, as OP, believe that it has gone too far in the wrong direction, and I don't mean that your opinion is being beaten into the ground - that's a case for fighting back with a superior argument - but sometimes things can become nasty and more than personal (which everything has to be to an extent to mean anything) at which time, if it survives the supervisors, then you have the ability to pull plugs.
In the case in point, I think that my memory of it tells me that the OP's beliefs were not simply refuted, but that it was done in an excessively mocking way, something of which I disapprove strongly.
People (such as I) who do tend to longish posts, spend some time fighting such things as dyslexic fingers which leads to frequent retyping, all of which is hugely frustrating, but since most posts are terrible anodyne and brief, few will be hurt by thread erasures: little in = little lost.
Rob C