I think the competition can be good. It probably helps to keep the companies striving to out do the others so we as consumers see more benefit.
As for why we argue I guess it's all about avoiding buyers' remorse. When someone who spent considerable amounts of money on a platform boasts that they can play "game X" which I would like to but can't, I automatically get slightly defensive and think at least I have "game Y". And of course it being the internet and tone of speech is often miscalculated we're suddenly in an argument and my mother's faithfulness to my father is called into question. :D