In a perfectly fair world, men and women would behave differently due to comparative advantage and specialization based on sexual dimorphism. Feminism, in seeking an equal world, denies reality and quite a bit of science. Also, like most Marx-derived groups, feminists are humorless killjoys
If you think Marxism considers classes to be evil and good, you have already demonstrated that you don't know Marxism. Marx was very clear that he saw the members of the different classes as effective slaves of circumstance, who acted out their roles in history out of necessity.
The capitalist, to Marx, not only is not evil, but is seen as a historical necessity that drives progress: Only through the development of advanced capitalist economies does production reach sufficient levels to be able to eradicate common wants, thus making socialism possible.
I'll not disagree with you that there are some feminist groups that follow the same twisted idea of what marxism is that you describe above, but they're by no means the only feminists out there, nor does their views have much of anything to do with marxism.
Marx clearly did describe things that way but the movements that called themselves Marxist (particularly Leninism and those Marxist groups influenced by Leninism, which given the influence of the USSR were pretty common among "Marxists") did tend to take the capitalist = evil approach (which fits more in with Leninism than Marxism, since Leninism major point of divergence was adapting Marxism to justify "socialist" revolution in pre-capitalist societies, thus rendering capitalism unnecessary.)
First, I would suggest that when you attack feminism in the abstract, you attack views that are actually currently and widely held by feminists. It’s a diverse movement, but there are actual mainstream views. Frequently even that will not be very helpful, so you will have to find out specifically which group of people you are addressing with your criticism.
If feminists can and do frequently criticise feminist views then so can you.
In that regard feminism is kind of like, say, conservatism or liberalism or socialism or nationalism.
Now, I myself do not have a problem with chucking even big and complex concepts like that on the trash heap of history if they actually do have a consistently disastrous history. You won’t find me putting much work into arguing against fascism or royalism or racism or antisemitism. I’m willing to dismiss those wholesale.
Feminism, whatever its faults may be in your view, is about a million miles away from clearing that, however. It’s absurd to even think it could approach that same standard of wholesale dismissal. It has no history of harm at all.
I.e. if feminism were the concept of atheism, the MRM would be the Westboro Baptist Church and not Christianity or belief in some deity as a whole. (That’s a slightly shitty metaphor since the frequent conflict MRM activists dream up between them and feminism is pretty absurd. Men getting harsher prison sentences? Men being disadvantaged during divorces? That’s often based on strict and old-fashioned gender roles, something many feminists abhor.)
As for feminism, what's your definition, and do you think other people are practicing that definition in particular? Look at tumblr posts discussing patriarchy theory sometime; somewhere amidst the paranoid depressed teenagers is a pretty well-defined belief system, and it's not yours anymore.
Beware whenever the term is brought up - it's usually used as an ad hominem.