Of course
rape is always wrong, whether done by a woman or a man and whether done to a woman or a man.
The trouble with women raping men is that that situation is even harder to recognize as rape (by others than the two persons involved) than the other way around. There is no tell-tale sperm to be found, often it is done by coercion not force, so there are no physical wounds to be seen. Often the man gets an involuntary erection during the rape, making him wonder himself if he truly does not want what is happening.
For all of these reasons, men find it harder to tell, and to prove, that they have been raped. And then of course there is the double standard that says only women can get raped because men supposedly always want sex with everybody and everything, and therefore never can be forced to do it against their will.