I'd call it a grammatical construction. Your brain already knows how to "typecast" a noun to a reason ("Why didn't the bill pass?" "I don't know. Politics."), it's just not usually grammatically "licensed" in this case. If you've been infected by the "because [noun]" meme, however, you have a construction in your vocabulary (we could say in your idiolect) that can be invoked to explain any instances of "because [noun]" you come across, with all the associated connotations you learned along with it.
It's similar to "Suddenly, bananas!" or "I accidentally the whole thing." I wish I could remember all the strange grammar I heard at MIT. Communities like the hacker community and 4chan are fertile ground for new grammatical constructions because people pick up and repeat the ones they hear while trying to preserve their meaning and connotations.
I still occasionally burst out laughing when I hear a funny turn of phrase at Meteor (which has a lot of MIT people).
I just came across a variant in the wild -- a Quora comment -- which puts the noun as the thing to be explained rather than the explanation:
That was the point if the question, though. "If God does not exist, then how come physics?" And the answer is, "You can just leave off the 'God' part and just ask 'how come physics?'"
I wonder why "how come [noun]" is recognizable as sort of the same thing.
It's similar to "Suddenly, bananas!" or "I accidentally the whole thing." I wish I could remember all the strange grammar I heard at MIT. Communities like the hacker community and 4chan are fertile ground for new grammatical constructions because people pick up and repeat the ones they hear while trying to preserve their meaning and connotations.
I still occasionally burst out laughing when I hear a funny turn of phrase at Meteor (which has a lot of MIT people).
Funny language is funny.