If you say a bunch of things that would get you in trouble on your anonymous account, then over a period of time say enough other things to dox yourself, all your old account content is still there. Over time a little slip here, a little slip there. You put enough pins on the board, someone can find you, hell you might even accidentally talk about something unique. Happens all the time.
It's a risk for no good reason. Your're taking the risk so that some other nameless person on a social media instance can go ohhhhhh that company did bad things.