The phrasing of "marketing tactic" would imply that DHH doesn't really care about or believe in the statements he makes…he's just doing it cynically as part of a broader marketing strategy. Anyone who's tracked DHH for a long time, particularly in his role as lead instigator of progress in the core Rails community, knows that's balderdash. His hot-under-the-collar style is legit, and whether you like it or not, it's just who he is.
Frankly, as somebody who despises pragmatism in the web development industry and thinks far more people should take principled stands on a wide variety of issues, I welcome his rants. Sometimes you can't move the needle by simply being "nice".