If you base your musical tastes on "popularity" then you're a bit of a mong.
To the comment on Green Day, if you hadnt heard, politics and music has been mixing since the 60's it doesnt matter who you are, you could probably pinpoint some sort of agenda in various bands and songs nowdays, its a fact of life. I dont think they regard themselves as "hardcore punkers" especially considering how far from punk their new album is.
Slipknot, I agree that subliminal verses is probably their best album musically, and probably killed off the majority of their fan base, mostly those kids who screamed out "theyre so like hardcore".
Wake up and smell the roses, $$$ makes the world go round, and in the end, "alternative" and "underground" are just terms to describe genres rather than the actual position of many bands/groups nowdays.