Most guys have no problem at all with girls getting into gaming. In fact, I tend to see it encouraged and desired. A lot of serious gamer guys hope for a gf or wife who is into gaming at least to some degree, for the commonality and because it helps avoid her looking down on the hobby.
Guys also don't have any problem with female developers. If there's a talented female game programmer or artist or music composer, nobody in or out of the industry has a beef with that.
What does bother some people are the women who don't really actually have any talent but still end up rising through the ranks within development for reasons which clearly have to do with using their gender and with white knights not holding them to the same standard a prospective male employee would be held to. Women who end up with positions in the gaming industry, whose set of skills and level of talent makes it clear as day that if they were male instead, they'd never have gotten through the door. That does irk people, and I think it should. There is a LOT of this which goes on. There are also some very talented female game makers who got into their position completely based on merit and skill. Hats off to them.
Similar phenomenon exists within the game reviewing world. This is another industry which was brought into existence by males, who now find themselves facing a situation where a lot of the prominent game review sites would rather have an attractive girl announcing gaming news, and what seems like a suspicious number of female reviewers gaining prominence. For myself, I would say that if a female reviewer is hired, or rising through the ranks... as long as she's on that trajectory by the same standards a male reviewer would need to meet... actual quality of insight and writing, etc... then more power to her. If, however, she's getting the job in the first place and then gaining prominence suspiciously rapidly, and this is to due with her gender in any way (she's attractive, or the company is thinking how it would look good to have more female faces on their reviews, etc.) then yea, that's irksome.
It's sort of sad that the nerdy guys who created the game review industry in the US are now almost incapable of getting hired because they aren't female, hot, or at least sporting a UK accent. I guess they've been deemed boring and old news. Ah well, inevitable I guess when an industry starts to move to more video news and such.
This is a process which repeats itself in so many walks of life. Feminists said they wanted equality. They were given equal access, but when there weren't enough women showing interest in certain fields, and not enough who really met the requirements... requirements started becoming two-tiered. Considerations which shouldn't be there seeped in. This happened in everything from politics, the corporate world, gaming, journalism, you name it. "This looks bad, we don't have enough females in upper management, in congress, etc" "Yea but Bob, we don't get very many female applicants and even fewer who are qualified..." "Damn the torpedoes! Hire them!"
Now when it comes to Sarkeesian? She's just a "fan" and a critic... but this same sort of thing applies even down at the level of mere players and fans.
Is a female competitive player being featured unusually prominently given her skill level? That can bother other gamers who play competitively, I think it's obvious why.
Oh and now there's this lady (Sarkeesian) showing up saying the gaming industry should make massive changes to content and sensibilities so that a small percentage of the gamer base, most of whom seem satisfied with how gaming is anyway, can supposedly be more pleased with games... at the expense of the much larger proportion of the gaming community, who will become less satisfied with it?
Of course that's going to bother people.
It feels like an interloper coming into an environment they didn't help build or sustain in any way, and only showing up after it's gotten to be a huge industry with cultural prominence... and then trying to change it. Not even trying to change it by starting her own development house and actually creating something, either... trying to change it via industrial strength whining from the sidelines.
Even still, I don't think she would have gotten nearly so much hate if her message had been strictly "there should be MORE GAMES LIKE ________" rather than being so heavily weighted toward "THERE SHOULD BE FEWER GAMES LIKE __________"
A lot of people suspected she wasn't really a gamer, but just an extreme feminist trying to infiltrate and destroy another thing males created and enjoy, and triggered by that thing reaching a certain critical cultural mass.. which always seems to draw these types. The same thing has happened in the atheist convention community, for instance.
Turns out that evidence has now come out to show she not only isn't really a gamer like she claimed, but also that her boyfriend provided all the knowledge and effort to create her videos.
The hatred is well deserved. If you look into her, she's someone who made a very calculated move to deliberately stir up anger, and then launder that anger through naive supporters, into filthy lucre. A despicable piece of shit, she is.