On this album, AC/DC has captured and perfectly transmitted the idea of MASCULINITY. It's a man's record full of men's images and urges. Rock 'n' roll is basically a man howling about his desires, and he often desires women, liquor, and guitars that sound like sheets of metal being destroyed by power tools. It's a very simple thing, really.
Yeah, pre-hairband heavy metal is pure guys music. Thank God for the 80s hairbands though, it was hard for metalheads to get a date before they invented the power balad (though my wife prefers real metal).
Good summary.
Another conservative element to the band - to make this all relevant - it's that they never deviated for a moment. Never recorded a rap duo, never went 'grunge', didn't "evolve" or go mellow by writing weepy ballads.
Start to finish, they were consistent and sure of themselves. The message is to be yourself, and the rest happens naturally.