Disagree. Blacklisting entire anonymity sets is legally and politically plausible (but I don't know how realistic any delisting is, certainly if mining is centralized it is much more realistic), and the anonymity set can't increase once blacklisted without culpability on the part of the users. Well at least for ring signatures. Thanks for helping me (re-)discover a key qualitative distinction which is very negative on ring signatures.
That ring signatures make blacklisting more useless or difficult, may be negative or positive depending on one's views on fungibility and blacklisting.