If the violence is sexual violence that would be the part I found "iffy." Or if the violence was graphic and extended. What would decide me is not the gender of the character, but whether the violence was gratuitous. (I just finished reading a novel by ... um ... someone not unknown on this forum, and there was extended violence, including sexual violence, but because of the treatment and the importance to the story I decided it was justified). I feel that it is often used as the simplest way to create a dramatic situation, to make a story seem more important and realistic than it really is. "Dark" is somehow considered more realistic than "light" though both exist in the world, both are real, and I think that some writers get away with poor plotting and bad characterization because all the death and destruction lends a spurious appearance of "authenticity" in terms of the story's representation of the human experience.
No, I don't think that a degree of physical abuse is required for a protagonist. And I am going to draw a wide red line between pain and physical discomfort (which are indeed inescapable) and abuse by another individual.
Because of the history of violence against women, I would feel more uncomfortable reading about a female being beaten to a pulp than a man suffering the same fate. That is, I would be more likely to question whether it was a necessary part of the story, although the answer I might arrive at could still be "yes." *
This would matter to me most if it were all happening in one series, or in books from the same writer. But if there seemed to be a whole sub-genre in which the females always die, yes, I would feel there was something wrong, some unpleasant subtext at work perhaps.
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*It occurs to me that the gender of the writer might come into it as well. If a female writer seemed to be taking a salacious delight (that is, if they seemed to be getting or trying to produce a sexual thrill) in mistreating a male character, whether the violence itself were sexual, or a male writer doing the same with a female character, then I would feel doubly uncomfortable.