Well seeing as the feminist movement is made up ofindividual feminists they're not all going to agree on the same things, just like all movements. It is not 'feminism arguing with itself', it's individuals having different opinions. It's nothing more than another social construction. Not all Christians think the same, not all conservatives think the same, not all work unions think the same because it is impossible for a whole group of people to have perfectly identical thoughts. Even the different sub-sections of feminism won't 100% agree on anything. It's not necessarily a negative criticism, it's just how it is.