Pretension? Of course there can be Pretension. Many people will defend their views, so of course it can be serious.
General discussion. People come here to discuss issues, people think and feel differently about things, that's the whole point of debating, to get your views out there, and to maybe, just maybe, make others see things the way you do. Of course there are those who don't listen. Those that argue against all logic and reason. Those who are simply opinionated and ignorant. Unfortunate, but eh. Ultimately everyone is allowed their opinions.
Of course if we all wanted to get along it would help if everyone was a. open minded and open to reason, b. not so quick to resort to questionable tactics of discussion like insults and the like and c. used alot more tact.