I don't like singling out Bowie as there were numerous artists involved in that documentary. I'm just about still in my 30's so I was only really aware of his music whilst obviously believing he was just a bit of an eccentric.
I've since read articles and as previously mentioned members of Led Zepellin, Rolling Stones etc are all implicated. The likes of Jerry Lee Lewis marrying his 13 year old cousin and even Elvis with Priscilla at 14.
I despise rap music, but the rock industry seems to have just as many skeletons in the closet. Think it's more linked to money, fame and entitlement than a particular genre of music.