Where does this sentiment come from? Reddit for the most part already does this. Twitter before Elon showed up did this. Most modern sites already do this
The only place I can think of where this is commonplace is 4chan, because they don't moderate.
Yes, highlighting bad actors over a course of time can be problematic. But the point in this case is the point out that we don't have the tools to deal with said bad actor. The tools that other sites have. It's not being said in vain, the goal is to make aware that something needs to be done so that people don't even see the bad actor to bring attention to them.
There is a purpose to the current efforts. I think everyone understands that constantly bringing attention to them will do no good, but the goal here is to bring attention to tools that are needed, so that it doesn't happen again, or at the very least to this extent.