Because they're completely different in sound. There are a lot of bluegrass songs about being poor and disenfranchised, yet nobody's saying that genre is anything like punk.
So? Bluegrass is not easy to pick up, so it completly defeats the point I was making. I know punk and hip-hop don't sound the same (or anywhere close to each other), I wasn't dropped on my head that much. I just don't understand (around here, especially) the idea that if you're into punk that hip-hop should be almost unlistenable to you - punk and hip-hop are easily emulated
with little money & training, and tend to attract disenfranchised listeners, usually tending to be younger.
They're not as dissimilar as people around here paint them to be.