Let me quote from the first post to this thread:

"I am a singer in a pretty hard rock band. This involves a lot of screaming, growling, etc...Now I am convinced there is no way to sing this stuff and not destroy your voice."

I am convinced that person is right. I used to have a book by a voice teacher who wrote that she was willing to teach 'Broadway belted,' but she refused to teach 'rock belted,' because rock belted destroys the voice.

Have you ever been really angry and roared at somebody with a growl in your throat? Have you felt the soreness afterwards? Can you imagine doing that as a career? Pfui!

vvvv, you mentioned a singer who can still hit every pitch very well. Trouble is, pitch is only one part of singing. A singer also wants range, tone, and variety. And longevity - a singer wants to sing his whole life long. That is, if he's really a singer and not just somebody who wants to make a buck in the music biz.