That doesn't even have so much to do with Brexit. It's just that if you look at the average forum poppulation and behaviour there are a few distinctive mindsets that guide behaviour in discussion and there is a fairly hard clash here between the "partisan debaters" and the "hard core scrutinisers". All this though can be completly placed within the field of social/forum behaviour.
Very briefly explained:
-the "Partisan debaters"* are the type who champion a side of a view and believe that in argumentation wins and losses must almost be seen as points won during a match. This often observingly translates in stubborn and even haughty behaviour by some posters while to the other side their views often blatantly do not hold up to scrutiny.
-The "hard core scrutinisers"* do not perceive that a argument is a match between who's views are superior for points. Hard core scrutinisers do not put that much value in how much knowledge one holds at any point, rather they foremost believe a person must be primarily critical and self observing for the function of independantly being able to find truth. In that sense there is no shame to asking questions for the function of scrutiny whereas for a partisan debater asking such questions might appear as showing weakness.
Get the "team mentallity" out of the debate, and let everybody hold himself to propper scrutiny and the scientific method to finding truth, then this issue wouldn't exist even if people held different oppinions. The problem is not that we are devided in views, the problem is that there is a conflict between the "standards of truth", withought that issue we would simply be split along lines of complexity.
*(source: dictionary of the quackish people)