Anyone who says "I'm not a feminist, but..." is not a feminist. Not because they don't “really” believe in equality or anything like that, but because they clearly don't want to align themselves with the radical potential of feminism. And that's fair enough.
I don’t like the discourse that says "if you're not a terrible person and in principle are pro-equality, then you’rea feminist, by definition, because we say so". Quite apart from being kind of arrogant, it's wrong, because belief in equality is nowhere near being a sufficient condition for feminism. It's all well and good to say that you’re against discrimination, but discrimination isn't like a coffee stain, something discrete that can simply be rubbed out of the world and then everything will be hunky dory. It's part of a system - in fact it's just a means to an end - and if you're not ready to see the system collapse, then your belief in equality is about as much use as a chocolate teapot in terms of improving people's lives in meaningful ways.
The systemic discrimination against women, people of colour, people whose gender identity or sexual/romantic preferences don't support the capitalist heteronormative dualist model, people who are disabled, people who have mental or cognitive problems - all of this is not a bug. It’s a feature. In order to continue existing in its current form, the capitalist white supremacist patriarchy needs to sort us all into neat little pairs in which one is economically and morally subordinate to the other (it also needs to sort us into larger groups in which one is always subordinate to another: poor to rich, black to white, female to male). That’s frankly what makes the world go round (nope, not money - this arrangement is what gets the money made).
You can’t get rid of discrimination - or inequality, they're two sides of the same coin - while leaving the rest of the system in place. The whole thing needs to come down, the world needs to change in startling and as yet unimaginable ways, in order for anything like “equality” to be a remotely viable proposition.
The revolutionary potential of feminism is in the fact that it sees, unmasks, explains, analyses and critiques all of the myriad mechanisms that the capitalist white supremacist patriarchy employs in order to make sure that these dualist, antagonistic alignments stay in place. There are of course some superficial changes from time to time. What used to be achieved through out and out coercion - physical and economic - of women into the subordinate role of dependent wife, now continues to be achieved through the blanket propaganda of the beauty industrial and entertainment complexes. Unlike liberalism, which sees this as progress, radicalism (and all real feminism is radical) sees this for what it is: same shit, different century.
This being the case, of course the majority of people find the few feminists who call out the duplicity and pervasiveness of this system aggressive, man-hating, extremist lunatics. If they didn't, we'd be doing something wrong here, frankly.
So when Katy Perry says "I'm not a feminist”, or Joss Whedon does, or Lady Gaga, my reaction is: of course you're not. If you said you were, you'd be lying. Your wealth and success are inextricably dependent on the beauty and entertainment industrial complexes. You are entirely in hock to the capitalist white supremacist patriarchy, whether you like to think of yourself as such or not.
So I never try to say to anyone "no wait, you really are a feminist, you just haven't realised it yet" (with the single exception of my sister, but that's a separate blog post). First of all, it's damned patronising. And secondly, it's wrong, as we saw. Anyone who says "I believe in equality but I'm not a feminist" is telling the truth, because a belief in equality is not even a fraction of what it means to really be a feminist.