David Heinemeier Hansson is a self-admitted racist. The evidence for this is a post he wrote entitled "As I remember London," which I won't link to but which contains clear statements that he believes that white people are superior to non-white people.
When called out about his beliefs, I have never seen him apologize or even attempt to offer actual fact-based justifications of his beliefs; instead he tends to dig in by doing things like analysis of sentiment about his opinions on Twitter, where the overall severe upward trend in racism fools him into thinking that a majority of people think like him.
All of the above shows an inability to engage with others in an emotionally-aware or emotionally-intelligent way.
(Note: I'm assuming that the original commenter refers to DHH, but I will point out that he is not in fact a founder of 37Signals.)