hmm... first thing I think whenever someone with previous long hair suddenly goes for the shaved head look is the balding syndrome. Some guys get into their 30's and suddenly realize, 'holy crap...I've got a bald spot', and the easiest way to hide it is to either start wearing a baseball cap all the time or shave your head and tell people you did it cause you think it 'looks cool'.
In actual fact the guy is panicking because he doesn't know how he's going to maintain his 'rocker' image without his long hair.

Satch for instance is probably getting into middle age right now and rather than look like an old guy, he's probably doing the same thing Paul Shaeffer, Bruce Willis and Andre Agassi did and go for the alternate 'cool' bald look.
It's either that or do the William Shatner thing.