I hardly think Sharon Osbourne represents metalheads. I've been to plenty of shows over the last couple of years where acts have made pro-Palestinian statements, and the only time I witnessed any pushback from the crowd was one guy at a hardcore show, who was promptly shouted down by the crowd when he called the singer of No Time a Nazi for saying he supported the Palestinians and calling Israel's actions a genocide.
The metal scene has plenty of real issues to answer for (hello, NSBM), but Sharon Osbourne being an out of touch bitch is not one of them, in my opinion.
Edit: Also, before someone searches No Time and assumes skinheads in an Oi band must be Nazis, have the lyrics for their song "Everything You Hate" in the spoiler.
spoiler
FEEBLE MIND, ARCHAIC THOUGHT
FEAR AND HATE, ALL YOU’VE GOT
A SHINING EXAMPLE OF THE MASTER RACE
I’M PROUD TO BE EVERYTHING YOU HATE
PROUD TO BE EVERYTHING THAT YOU HATE
THE REICH IS DEAD
SO TAKE A HINT
GO GOOSE STEP
OFF A FUCKING CLIFF
The letter, released by the Creative Community For Peace (CCFP), came in response to the airing of Gaza: How to Survive a Warzone and the resulting row when it emerged that the film’s narrator had family ties to Hamas.
Calling for a “full commission of inquiry” into the actions taken by the BBC surrounding the documentary, the letter said it is time for the broadcaster “to acknowledge that it has a systematic problem of bias against Israel”.
Many other big metal names have done similar things. Mostly from Germany.
And? That some people within a certain group have supported them hardly means you can say that it's a problem with the group as a whole. I also saw a dozen metal bands who are explicitly pro-Palestinian, and have expressed that in their shows and online.
Metalheads as a whole haven't done something to be a disappointment, some prominent figures within the community have.