Mods. Whenever you see community/forums take the wrong turn - it's always mods. Reddit is now extremely leftwing, to the point of pushing communism and banning everyone with even slightest conservative view-points, and that's where mods come in - mods can ban account for life sitewide. This was the first mistake

Second mistake was banning and removing subs that were controversial and might or might not have been frowned upon by advertiser.

Old Reddit used to break news first, now reddit is just 9gag