You hear about it a lot on HN because people write interesting articles about it. Remember, most articles that are submitted aren't being upvoted. There's probably someone writing about how their ImmutableSet implementation for Java is the best thing ever, but it's not being upvoted because the community doesn't consider it interesting.
Yet, most of the proselytism int the Ruby community are different shades of "Programming with this language makes me very happy, I'd like everyone to be happy as well". Of course it's not always as clear cut and there is sometimes much to be desired in terms of behavior. But that's where the Haskell in MY PERSONAL OPINION (so to take with a pinch of salt) is slightly different in how it seems to be variations of "Haskell is a superior language, everyone that doesn't use it has not reached enlightenment"
TL;DR: Ruby people can be annoying like hippies can be annoying, Haskell enthusiasts I've found to be more akin to the Jehovah's witnesses of programming.
And just so we're clear, I am going on a slightly provocative/trollish bender here, one that I hope will not offend too much, it's all in good fun.
If you disagree, how about citing some sources? You're good at coming up with analogies, but coming up with analogies is like being Hitler. What?
Haskellers being compared to Jehovah's witnesses is even more wrong. They're more like scientists, maybe of the climate change variety: most of them keep their heads down with a dedication to improving the state of the art, but when they go public it's with good reason and people should listen rather rejecting out of hand anything that challenges their ingrained worldview.
Ruby, on the other hand, is pretty unremarkable. It doesn't really offer anything beyond what older languages like Perl and Python, for example, offer.
That facilitates dsls and I believe it's important enough to note as significant.