I reject the theory that women are systematically oppressed by men in modern Western society, as it is baseless; I see a lot of people claim "patriarchy hurts men too" while the whole point of patriarchy, according to many, seems to be "patriarchy benefits men and not women", which is nonsense as women clearly benefit from prevailing perceptions of femininity and masculinity (just as one example, consider a woman physically assaulting a man in public; unless it was extremely severe nobody would care and would probably just laugh at him, whereas a woman can, if in public, bank on the protection of those around her if a man assaults her - you can say this arises from our "patriarchal" view of women as weak, but it's obvious that even if this is the case that the "patriarchy" system can work in women's favour. Not exactly an empirical example but I hardly think you'll disagree)
And if there are so many feminists actively working to end real oppression, in third-world countries, then they don't seem to being very vocal about their activities. I've heard a lot of people say "this is bad!" but I haven't seen anybody doing anything about it. I do agree that men's rights movements are too focused on bashing feminism, but the problem is that if anyone actually does talk about men's issues then the Tumblr and Twitter feminist mobs have a tendency to shout them down for misogyny.
edit: Also I think a lot of people, myself included, dislike the heavily sociological and sometimes nebulous approach feminism seems to have. It seems to work under the assumption that all our perceptions, all our biases, are societally engineered, ignoring the biology of men and women and the very apparent differences and general trends of behaviour. We should look at everybody as individuals, but feminism takes that too far by trying to act as if, without this vaguely defined, unproven oppressive structure, we would see no difference in how men and women behave and what men and women choose to do on average.