[downerending]

My impression is the reason is that there really isn't widespread agreement on the harmfulness of such communities, so they're sort of trying to split the middle. And perhaps also to advocate for seeing them as awful, per corporate sentiment.

The principal example that comes to mind is TD, which seems more obnoxious and tasteless than some sort of evil.

Subs that truly are beyond the pale by wide consensus seem to get dropped immediately and without objection.

As to not wanting to win, well, yes, dropping everything controversial means losing a lot of page-hits, and as a business, they're likely wary.