1) There's nothing that makes bad fodder for discursive meditation, provided you can reject ideas as well as incorporate them.

2)it's mostly due to the fact that each niche follows the same core structure of having an ingroup of "smart people who know what's up" and an outgroup of "Easily mislead idiots". Most if not all political groups have this dichotomy, which makes them unable to debate with other sides because the assumption is always that the other side is wrong.