He's regurgitating racist tropes. Whether he knows that or not I don't know. He might be racist, it might just be Dunning-Kruger around whether he can speak authoritatively on social issues (in his post there's no attempt at original thought, just copy-paste).
But...it makes it a little difficult to build an inclusive open source community with that at your head.
Yes, it clearly does. The point of that comment depends on the supposition that Trump was praising objectionable groups, so as to liken DHH's behaviour to that. But it is well established that Trump did not, in fact, praise objectionable groups. And reading the full text of Trump's interview reveals nothing objectionable about what he was saying.
But...it makes it a little difficult to build an inclusive open source community with that at your head.