Continuing to read things on it, even through Nitter, is in the interests of Twitter/X and of the people who continue to support Twitter/X by posting there.
Tell the people who use it no. The decent people won't hear them on Twitter/X, and the decent people will wonder what's wrong with them if they persist in supporting that thing.
Tech industry circles nowadays are sometimes tinged with individualist selfish "take whatever you can" thinking, and anarchic or even underhanded methods. Including the thinking "an express no doesn't mean no, if i can find a way to take it from them anyway."
Grassroots collective social action can work, if it isn't constantly undermined by selfish and short-sighted taking.