The problem is that doing so would cause most of the users to revolt and leave, and given they've become an advertiser click whore website now, they'll keep as much autism as they can get away with to retain users while getting rid of whatever will not cause a dent in their bottom line.
Another problem is the culture is too set in it's ways to change by both inertia and design. Unlike All The Tropes, which forked and decided early on to fling most of the autism into the abyss (like Troper Tales, the Pantheon, Fetish Fuel, a huge chunk of the Just For Fun nonsense, etc.), TV Tropes largely stopped trying to clean itself up after the second censorship purge, which resulted a mass defection (and not just of the guys who would found ATT) of users, and while the new owner is less an asshat than Fast Eddie was, he still wants to make money, and most of that autism draws users, which draws clicks, which draws money.
