It's not a 'No True Scotsman' argument, I didn't claim she wasn't a feminist I claimed that your argument is invalid because there are terrible people in any group you may choose to associate with. I can use the exact same argument for your 'second' reason which is really just the same as the first reason but how about I give you another angle from which it is stupid.Helmholtz Watson said:Valerie Solanas has to do with Feminism, and no amount of no-True-Scotsman fallacies will change that.
You want another reason? Ok, one reason would be that I don't hear many feminist leaders denouncing people like Mary Daly, and as such I have to ask, "why not?" . If people like her are against mainstream Feminism's messages, why not publicly denounce them? A second reason would be that the word has a gender bias. If it was to be changed to something more gender neutral, then I would be behind it.
You don't hear feminist leaders publicly denounce Mary Daly for three reasons.
1) For the same reason they don't denounce you, she's simply not relevant enough for anyone to talk about.
2) Because the time that she was relevant was almost 40 years ago, and at that time while her ideas were wrong headed they were important to building the framework for feminism. In times of extreme crisis sometimes extreme voices are necessary.
3) Because you're not paying attention. Just a quick search of Mary Daly shows a number of feminist magazines and blogs feel that while she should be respected as one of the early voices of the movement, her ideas were too extreme for our modern time.
So far as your third 'argument', well I'll say that when people get down to linguistic debates it's generally because they don't have anything more relevant to say and refuse the admit they're wrong. Still though I'll explain. The reason Feminists are called such is simply provenance, when the movement started is was pretty much all about women, because women were so far behind they needed loud and dedicated advocates to even hope for some level of equality. Now, even though things are much more egalitarian (although certainly not yet equal) we respect our origins by keeping the name they chose.