That said: there are issues with saying the gaming community is "white males, college educated, racist, misogynist." It's a terrible generalization that's caused a lot of backlash. First, it puts at gamers the defensive, such as boogie's youtube video "I'm not a bigot, are you?".
Second, it marginalizes the rest of us who are not white, not racist, not misogynist because we either have to defend ourselves, or deny affiliation with something we enjoy.
Third: because this movement and general atmosphere is coming from outside gaming culture, it places even more people on the defensive because it's coming from a movement that criticizes, but has done little to actually change things.
I'd like to respond to each of your points with my opinion.
Firstly, I do not see a problem with generalisations. They are useful and fundamental tools of discourse and logic. They are only a problem when they ignore certain contexts or nuances that may alter one's perspective of the topic. In my opinion, it is a fair generalisation to say that the medium of video games, on balance, is a largely backward one in many respects.
I doubt that many people are saying that the video games community is
literally made up entirely of white, misogynistic males. The point of this generalisation here is that some ideologies have predominance over others. The industry as a whole, from every stage of the supply chain, is therefore
predominantly racist, misogynistic, and gender-normative. We can see this in the products, where white male protagonists have the most representation while female characters are reduced to tropes; we can see this in the development process, where female developers are discriminated against by co-workers or bosses and given fewer professional opportunities; we can see this in the audience, where the slightest sign of "politically correct" content in their video games is seen as a threat to the status quo, and where female gamers are disrespected in a number of ways in both online communities and single-player content.
This generalisation
does put people on the defensive, there is no doubt about that. Nobody likes being branded a racist, or a sexist. These are terms that people will immediately jump to deny without first considering it as a possibility, without considering that not all actions need to be malicious in order to be hurtful, or without considering that racism and sexism can be unconsciously propagated. Those who are critical will examine and reflect upon these accusations, and those who are stubborn will decry these as part of a "social justice warrior" epidemic. All of this is unfortunate – and perhaps there are ways to mitigate this, by framing these ideas in less hostile ways – but a message is ultimately only as successful as its receivers' ability to comprehend it.
Secondly, it should be evident to the critical reader to whom an article or writing is geared towards. Those who are not racist, misogynistic and so on would understand that they are not included in this generalisation, that the article addresses systemic issues which inherently necessitate a degree of generalisation, and would furthermore support such activism that aims to dispel these issues.
Thirdly, if you are referring to the feminist movement, then I would heavily disagree that it has not effected change. It undeniably criticises, but I cannot think of a social movement in history that did not. I do not see criticism as a bad thing, either.