As near as I can tell, she isn't saying that objectification, sexualization, or violence in video games directly causes rape or violence towards women, but that it causes a desensitization towards such acts in real life and an increased willingness to believe that, for example, women promote or encourage the act of rape by their actions.
That's not quite the same as saying rape in video games=rape in the real world.
But what she does say is still fairly lame, insulting, and lazy. Citing "studies" without giving specifics, the not atypical trick of failing to mention whether an "observed effect" in a media study could still be measured hours, days, or weeks after the media viewing, topping off with a pseudoscientific "and if you think it's not you, you're wrong, it's especially you"- Oh come on. This is the kind of bullshit that kills any attempts from non-true-believers to actually engage.
"...Well, since you've all got it wrapped up in a bow that says any dissent is automatically disregardable, I guess I won't bother..."
I'll be honest that I have a strong belief in free speech and expression that trumps any number of other causes, however well-meaning, under the premise that without free expression those causes could never establish themselves in the first place (and all too frequently good causes are eager to slam the gate behind them once they start to gain some momentum). I have to believe that we're capable of taking in information and processing it in at least a semi-rational manner rather than immediately going off half-cocked on the manipulation embedded in the message. I believe that seeing an erotic movie might make someone sexually aroused, or hearing a pumping rock song might make someone aggressive, or seeing a story of heroism might cause one to feel a surge of patriotism- but that those things are largely temporary, they're part of a broader experience, and they don't tend to unilaterally cause someone to act in a particular way without colliding with a million other pieces of learning and experience that have formed the person.
If I had to concede that we were such shallow meat-machines that we could be completely over-written so easily- even without that being the author's intent- then video games wouldn't even be in the top hundred places I would be looking to swing some hammers. Politics, commercial advertisement, religion- if we're all such sheep, never mind a little chauvanism; we're ready to rip the entire human race apart for the first PhD in Communications to get their evil genius on.
But I don't think we are, and I think it's pretty damn sad that there are going to be people citing Sarkeesian's alleged authority to suggest otherwise.