They do have a footprint in the early evolution between hardrock and metal which was not the fine line thats been drawn, twisted and moved all over hells acre during the decades. They were considered part of the metal scene on the more commercial side in those early years. Laugh or poke all you want, cant change history but does indicate some ignorance of it. Today they can clearly be seen as blues based hardrockers but "metal" evolved in part out of the rowdy hardrock scene.
Angus may well have been one of the first extreme "headbangers" LOL
They are a great band, it doesn't really matter what kind of music they play (no, they're not a metal band). Fact is they deserve respect, their gigs are always fun and albums like Back in Black just can't be ignored.
Yes, I can tell you have a real thing for diversity with bands such as Deathspell Omega, Bloodbath, Cryptopsy, and many other genre-jumping black and death metal bands in your last.fm list.