Because the same legion of full-time Eric Cartman impersonators smears the same hateful dogshit over normal comment threads. This is a lot more effective than individually banning every member of the inevitable asshat brigade. There’s room for instances that federate with them, but it probably shouldn’t be the default.
The problem is that the articles from exploring heads take an average of two sentences to reach an obvious and malicious lie. There is no room for discussion under those circumstances.
For those who don’t respect the authority of conservatives as the arbiters of reality, they have no purpose except as a glimpse into the abyss. It’s like having your stream of memes interrupted every few pages by a graphic crime scene photo, only with the dread that comes with knowing that the criminal has a wide support base.
Don’t forget a bathroom trash can with a bag.