This should answer your question:History of the Use of the Sigil of Baphomet in the Church of Satan
The CoS has its version, which is the symbol of Satanism and the Church of Satan
. Derivations of Baphomet symbols from historical sources, uniquely rendered versions, symbols of inverse Christianity, etc., are all free game. Most "bands" that use them appropriate them for shock value, to evoke "horror" or rebellion--these bands are rarely even remotely associated with Satanism. Most probably don't know what Satanism is, beyond what they've seen in horror movies. There is a long, rich history of incorporating demonic & mythological imagery in art--and we certainly wouldn't want to get in the way of that.