It's easy to say this when you already have an incredibly successful channel.
For the majority of of talent pandering to ANY type of audience that will be loyal enough to show up and watch your streams in an incredibly successful and smart strategy. While the threat of audience capture is real - there are plenty of examples of streamers who used their initial core audience to grow and then replace them with new fans. As long as there is this edgy audience looking for vtubers to pander to them it will be a good idea to engage them. The only genuine worry is that having an edgy audience might negatively impact the ability to join a large corporation who would want to avoid negative fallout.
If they want people not to pander to the edgy audience they need to create some kind of alternative, of which none exists. Moral outrage will do nothing when talent sees that pandering leads to views and donations, while NOT pandering does nothing for them. Until talent starts growing slower while pandering to edgy 4channers than not, they are incentivised to do so by the only metrics that matter - views and donations.