All of that is technically correct. And I completely get why a low-income, lonely white dude is sick to death of hearing about how his movies, video games, and jokes are racist or sexist or homophobic. The logic is almost impossible to argue with: "If their problems as women are on the level of getting Hollywood to cast a plus-size Wonder Woman, and my problems involve not being able to afford heat in the winter, then it's downright evil to belittle my real problems while demanding I worry about that trivial SJW Tumblr bullshit."
In other words, why can't we start treating each other like individuals based on our position in life, and just drop all of this race/gender stuff that just clouds the issue? Wouldn't that be the fastest way to make things better for everyone?
Sure, and we could totally do that, if we were merely people. The problem is that we can't just collectively agree to make the context of history go away, any more than a bunch of leaves can get together and decide that there is no tree; the roots of history are still feeding us. Blacks are still stuck in neighborhoods with terrible schools and no job opportunities where they're being groomed for a lifetime in the corrections system. Women who want to get jobs as software engineers will find themselves in offices that are 84 percent male.
So, while race is a social construct as are lots of gender roles*, that doesn't mean they're not real -- the systems we're living under today were all built with them in mind.
And if you are a white male in America, you're among the winningest of the winning tribes -- again, even if your own life is a disaster. This is why people say you have "privilege." It doesn't really refer to anything you have, but what you don't have. You may still get shot by a cop some day, but you won't get shot because you're white. As a male, your boss might be less likely to flirt with you, but will be more likely to take your input seriously. And so on.
Changing that doesn't mean they're winning, and you're losing. This isn't about you. There is no "you" at all, outside of this larger context. It's about continuing this winning streak humanity has been on, and trying to build a world in which everybody -- from the poor white dude in the trailer park to the black trans woman in Russia -- has the best possible chance to make something with their lives. We can disagree about how exactly to do that, but as for those people talking about the "good old days" and getting back to "traditional" values? The best thing I can say about them is that they can't possibly know what they're asking for.