it still isn't a group and you can't change what it stands for. you can't define it by its people, you only define it by its ideas (and divisions if necessary). the same goes for any religion.
you can argue all day about who is and isn't a shoe lover. at the end of the day, everyone still loves shoes, but they might individually express that love in different ways. if you're going to refer to an ideology as a collective, you have to make the distinction clear. feminism is an ideology. feminist is a person. people are fallible. ideologies are ideas. you have to concede individuality whenever you're using a collective, otherwise you'll probably start to handle people as constructed caricatures rather than as people.
basically, don't lump everyone together and then point out a big dummy pants and then say "AHA THE ENTIRE PANTS STORE IS DUMMY!" because that's silly, esp when the pants store isn't an actual place that exists, but rather a sociological phenomena existing as a result of the idea of selling pants.
