they definitionally aren't complete or went-out-to-do-16-hours-of-research, because the person is thinking about it, right there in front of you. Sometimes people do that, but if you hold everyone to that standard you are going to be disappointed because even those posters are mostly the everything-else with the occasional hundred-meter-scroll.
they aren't a news outlet. it's years of accreted thought and readings that often just came together for them, or a new way of explaining it.
if you want complete thoughts, go find a macroblog