The world is one giant complicated mess, and as humans, we aren’t wired to deal with that.  Given a chance, we will always simplify, reduce, and otherwise ignore rather than deal with possibilities.  This is a gross generalization, and not everyone does this all the time.  But we all do it sometime.  And some of us do it a lot.

Setting aside the political, social, and religious connotations of this notion (and there are plenty of those indeed but that’s way too complicated to get into), I see it whenever humans immediately thrust one expression of media into competition with some similar expression.  It basically seems to stem from a desire to keep things neat and tidy.