It's the really horrible bit that deserves focus.
Are you looking to round out the racism discussion derail bingo card, or just completely clueless?
It doesn't help that a lot of the language of power dynamics was co-opted by the self-help community, which can often be legitimately criticized in these ways.
Pointing out an ugly tone does not mean you think it invalidates the argument.
"Yes, you're angry but instead of talking about why you're angry let's talk about how the way you expressed your anger is inappropriate".
Its an inappropriate topic change, directing blame at the author when it's really not warranted.
As a minority, it is really, really hard to change or rectify the corruption of the majority by trying to fight them head-on. These sort of revolutions worked when the majority of the people overthrew a corrupt minority that had excessive power. However, thinking things over, I'm not sure if the author is even really out to solve the large racial issue in general with this post. I don't think that was his point, so maybe I'm offering suggestions to a goal that he never had in the first place. If this, like most tumblr posts, is just to get it out in writing so he can think clearly and draw attention by the public to the situation, then yes, it works.
I've been around these kind of complaints in person, and while I know that the injustices taking place are horrible and uncalled for, I also know that the complainer is also (not-so-subtly any more) racist as well. Perhaps he wasn't before he entered the school system or the workforce (not necessarily this job), but saying things like dumbwhite*, bringing up colonization like slavery as property is taking place in his neighbourhood (he's going through legal to get this solved, something slaves could never do), and repeatedly bringing up that his tormentors are white, male, rich, etc. just shows that he's brought his own racist viewpoints to the table.
This reminds me of the atmosphere in South Africa years after apartheid was rescinded. The atmosphere, not the gruesome crimes. Perhaps it can be justified, but it sure wasn't how MLK Jr. or Mandela (at least after he became president) attacked the problem and it's only good for outrage, not getting anything done.
White guilt isn't going to help solve racism, but I agree that the author deserves some justice.