I believe there are still good rock music available.
They are just not mainstream and you have to dig deeper to find them.

The bad thing about music industry now is: it perceives what can be shopped as a 'trend' and blatantly exploits the trend until it dies. Unfortunately the trend now does not have much to do with rock music.

Combined with the media's penchant for labelling certain genre of music as 'obsolete' or 'over', this can't be good for those genres that are being discriminated against.

I am still wondering WHY can't the music industry try to have different musical genres at the same time, in order to cater to everybody's tastes. I believe this will bring even more revenue to the industry. Let the Billboard chart have rap, melodic rock, r n b, glam, grunge, pop, jazz, blues, disco, metal etc at the same time.

Of course as rock music fans, it doesn't help the genre if you judge certain bands are 'so dated in the 80s' without even giving chance to their most recent musical output. This just propagates the stereotypes painted by the media.

So it's a combination of factors.