Creative, perhaps, in a purely artistic sense. Even here, I think it's arguable. But, it's still definitely an art form and art is creative.
"Creative of modern culture" is what rock music was... a pretty defining quality of what rock music was. It produced youth culture. Mainstream culture. Memes. Fashions. Ethos, etc.
Currently, there is not a single bonafide "rock star" under 50. Even the idiomatic term "rockstar" has fallen out of use.
This is more to do with the effect of the web disrupting and decentralizing the ability of corporations to create and curate a homogeneous cultural experience than the failure of rock as an art form. "Rock Star" is a commercial construct that can't exist in a world of Spotify and Soundcloud and hyperlocal community-created genres.
