Like any social impulse, feminism is not so much one thing as it is an expression of competing trends which relate to women's aspirations as free individuals. What kind of feminism we identify with -- or whether we identify at all -- contributes to the broader picture of feminism which prevails within society.
For example, I know many people who don't identify with feminism because the model they acknowledge doesn't reflect their concerns. By choosing to disassociate, however, these friends yield what should be contested terrain to their rivals. Feminism then grows in stature as a movement which does not address the concerns of all women. The practical consequence of rejecting "feminism" as inadequate is to preserve its inadequacy.
To the extent that there has been an organized attempt to understand power relations from the perspectives of women, it has come under the banner of feminism. Either we don't care about this particular course of study and action, or we propose some viable alternative. Short of this, we must advocate for the kind of feminism which reflects our values and concerns.
In the same way that the Industrial Workers of the World seeks to establish the "one big union for all workers," a Wobbly feminism must truly be a "feminism for all women." A feminism for all women will always be an anti-capitalist feminism, because the needs and aspirations of all women cannot be reconciled with capitalism. For this reason, a consistent feminism will always be a socialist feminism; a free feminism will be a libertarian feminism.