I wonder if women complain because it makes it more convenient for men to engage women in their games, by analogy; especially if they are not in the best of moods. Like for example the SO starts to nag or play some game that may involve some male friends. In the past, the guy would have to go find a chick to "get back at her" and that could be more expensive and time consuming for guys than it is for women; porn on the other hand, involves a variety of women whom a guy can have cybersex with, even if only asynchronously.
So, as far as I am concerned, porn has "leveled" the playing field somewhat by giving guys access to a variety of women that they would not have had access to in the past. That could be what annoys women the most; a form of male equality while not becoming female.