I see people hate on different types of music all the time. People say 'rap is crap,' 'emo is for whiny little bitches,' etc. Just because you've for some reason or another picked a particular genre(s) of music to like doesn't mean you must rule out other genres. It is possible to like death metal and usher. As a punk fan you don't have to hate rap. People tend to pick a genre of music, get into the mindset, and go along with the crowd by saying other music sucks.
Furthermore, just because a band gets played on MTV or has a hit song on the radio doesn't mean they've suddenly 'sold out,' or that all MTV-established bands or artists suck. You can't blame someone for wanting some money and fame, but if they actually do cash in on a different sound that's more popular and don't stay true to themselves, that's a different story.
Bottom line is: like music that sounds good to you. Don't hate music because other (insert your type of music)-fans hate it. I am a fan of good music, no matter what artist or genre.
smokin weed flippin keys makin crazy gs