IMO there's a lot of straw here -- from what I've seen in my encounters with a whole lot of different left tendencies on social media, pure "identitarianism" is relatively minor. The overwhelming majority of those fighting for racial and gender justice are thoroughly intersectionalist, reject a focus on racial and gender identity at the expense of class, and see racial and gender oppression mutually interacting with and reinforcing class oppression and serving the interests of capital. To the extent that anyone in the real world elevates "identity politics" over economics and class, it's center-left establishment interests like supporters of Clinton. Intersectional theory was actually invented to counter the pure identitarian movements of the 1970s (like Second Wave feminism).
And if there's anything that's guaranteed to set off the "mansplaining" radar of women and POC and actively alienate them, it's an article by a white guy trying to explain that structural racism and patriarchy are really not all that bad.
In short, this article is an attempt to "fix" something that mostly doesn't exist outside the imaginations of brocialists like Freddie DeBoer, and it will be incredibly counter-productive in its effects. If anything, creating a dichotomy between identity and class will directly serve the interests of capital by creating new racial and gender tensions in the economic justice movement and making it easier, not harder, to fissure economic and class justice movements along racial and gender lines.