Because that might be part of a much larger chain.
Additionally, what's gratuitous in one set of eyes is natural in another's. For example, I find Java to be a gratuitous (mis)use of classes, but others, like Smalltalkers, find it to be gratuitously procedural. :-)
Being right, does not endow the right to be rude; politeness costs nothing.
Being unknowing, is not the same as being stupid.
Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence.
Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.