So, I heard people saying that Fun wasn't a "rock" band. Now, I don't agree or disagree with this statement because, to me, it doesn't matter.
To me, rock music is anything with a drum kit and a guitar, but there are tons of variations that can fit the bill. If bands wants to call themselves "rock" or "pop" or "indie" then just let them. Who the hell cares?
Honestly, do genres even matter anymore? The more time people spend trying to fit bands into genres and influencing them to coincide with genres, the more the creativity of musicians is stunted.
I don't care about people who want to force sub genres for the purpose of sounding like an elitest jerk, but when I ask someone what genre fun is, I would like an intelligent and well-thought answer.
Rock is anywhere from Alexisonfire to ACDC to The Black Keys in my book.
And I just don't think fun is rock.