This is a difficult and rather controversial topic, but I thought it was worth weighing in on, especially as it is something I have run into a lot in discussions.
First of all, I have some basic beliefs around the issue of men's rights and masculism. They may appear contradictory, but really, they are just in a delicate and polarized balance.
1) I agree with Robin Morgan on this: "The oppressors are indeed FUCKED UP by being masters (racism hurts whites, sexual stereotypes are harmful to men) but those masters are not OPPRESSED. Any master has the alternative of divesting himself of sexism or racism — the oppressed have no alternative — for they have no power — but to fight. In the long run, Women's Liberation will of course free men — but in the short run it's going to COST men a lot of privilege, which no one gives up willingly or easily." A great example here is the age old belief that in certain situations women are "asking for it." But that women even CAN BE "asking for it" is saying a lot about our attitudes towards men. That apparently they are so fueled by a desire for sex that they will ignore when a woman says "no" and that there is an excuse for that because they are men. So men are just brainless humping raping animals, and we can't hold him to a higher standard than your average African lion pinning down the lioness who's in heat.
2) I do not think the women's movement has achieved total equality for women yet.
3) I do think that some of the issues MRA's bring up need to be addressed, e.g. paternal rights, unfair domestic abuse policies, and rape. Men are raped too. Men are abused by their mates too. Men deserve access to their children just as women do.
4) I do think the stereotyping I see of men and women in movies, on tv, and in our culture at large hurt both men and women. Again, refer to the "asking for it" example, stereotypes like that abound.
5) I do not think it is feminism's job to address any of these issues. As Morgan says, I think eventually, if feminism achieves it's aims it will free men as well, but doing so should not be our focus. Feminism's focus should be on freeing women. But I do not see why feminism could not support a thoughtful men's movement, that is assuming that any such thoughtful men's movement would agree with feminism's aims.
OK, those background perspective things out of the way... I was reading Shakespeares Sister explaining what an MRA is. Clearly this explanation is targeting a certain kind of MRA. And unfortunately, the vast majority of MRAs I have run into do in fact fall into this misogynistic-ultra-right-wing-super-conservative-douchebag category (Promise Keepers anyone?). However, there is such a thing as a pro-feminist men's movement as well (also check out: NOMAS and MRC).
So, does lumping them together help anything? I don't think it does. If anything, it shows the same flippant disregard for some important issues that early feminists were subjected to, and I don't like that sort of superiority at all.
By all means, ridicule the misogynistic-ultra-right-wing-super-conservative-douchebags. I don't have time for men who hide rape apologies and veiled misogyny behind paternal rights. But if we really expect for men to understand our rage at personal circumstances, and our feminist issues, I think we should try and pay the same courtesy to them. At the very least, careful listening will help us pick out the douchebags more quickly.