Agreed. Unlike the 80s trend of "big hair", metal haircuts these days cover pretty much the whole spectrum. Heck, I'm just looking at BTBAM and you got 5 different styles right there.
I love to see a good Skullet at concerts (bonus points for corpse paint that goes up the bald head) but really I think people should be encouraged to dress/style themselves however they like, regardless of what music they listen to. I'm a weekend warrior with a regular 9-to-5 so I can't really do anything exciting with my hair.
One of my favorite things about metal is how accepting it is, you could get out of your office job throw on a band shirt and headbang to whatever and no one gives a shit. Also Halford gave rise to the bald metalhead in 1990.