To be honest, I don't think Rock Music exists in the same way as it did in the 1970s. And while I understand the argument for there not being enough creative artists in the industry, it's also a matter of who will sell records. That's nothing new.
But back to rock music, it's not the same. There aren't as many bands or groups, it's more of a solo artists world which means the media and the record labels can focus on one group of people.
The term rock star has changed since sex is still prominent but it's used to sell records and not establish legends. Drugs are no longer in vogue and I think that all changed with the 1980s Drug Wars and AIDS outbreak.
I think Rock Stars are all interesting, but in terms of providing music, artistry, and character I would hands down pick the 1970s.