I rarely put downsides, only when, in general, a completely idiotic answer in my opinion. Like rubbing in some kind of religious or political crap. By putting a plus on a decent answer, you just automatically "minus" all the others.
That's what I really miss here is the pluses for the questions! Indeed, sometimes (very sometimes!) One comes across such questions that no answers can be compared with him. Also, minus questions would allow "pouring" down children's nonsense about "why does she not send me a photo to the FB?" or "What is your favorite composition of <>?"
And yes - this is not a platform for discussions, there are social networks for this.
I will add that TheQ is not a forum for young marmots, where the winner is the one who writes more comments to CAPS LOCOM, but a service of expert (supposedly) answers. There is generally no need for comments: the answer is either correct (reasonable) or not. Sometimes it makes sense to comment only on the scientific or technical details of the answer and then if the answer is generally sensible. And every time go broke, explaining to a person why camels do not fly and it is really a pity for time.
Our time) If the answer is completely stupid, then you can still explain. But if any clarifications that require a long answer are just laziness or a pity for the time.