First of all, I enjoy punk rock music and I enjoy the music of the Sex Pistols. I refuse to believe however, that their refusal to accept this award was a genuine act of protest. It was completely predictable. Their anti-establishment behavior was interesting at their inception because no one else had the guts to do it. These men are no longer bored, hopeless working-class youths, so why are they still mad? They fact that they self-destructed doesn't really solidify them as some sort of symbol of a movement to me, it just makes me think that Johnny Rotten probably was annoying to hang out with and Sid Vicious was a drug-addict who couldn't get himself pulled together.
I believe turning the award down is exactly what most people who follow them would expect them to do, and therefore is in fact not the "punk rock" thing to do because it is predictable. If they had accepted the award, lots of people probably would have said they sold out. This is the eternal catch 22 of a punk rocker. The truly punk thing to do would have been to show up, accept the award, and then I don't know, say that they were honored. The Clash did it a few years ago.