re: MTV… Allow me to quote the Dead Kennedys:
Actually I never made up my mind on them at all. I don’t think I can even remember what their songs sounded like. What I said was that if I were inclined to respect them or any other musical act, seeing that musical act on MTV would bother me more than hearing it on the radio. Maybe that statement there didn’t have much merit… I’ve seen way better acts on AMP back in the day than I ever heard on any top 40 station, but anyway the point is in this case their presence on mtv didn’t “convince me” to dislike them.
I have, however, seen too many groups produce inspired albums only to get sucked into the mtv world, and mainstream production contracts that inevitably follow, only to walk out the other end with very little of interest for me. So if a group I was particularly fond of showed up on mtv, I would be disheartened because I would have good reason to believe that their ‘genius’ would soon be brushed aside in favor of mass-friendly party noise.
Being old, I do of course agree. 
The problem for me isn’t that it’s “worse” than the music i grew up to like, it’s just that popular music addresses the concerns of it’s target audiences, which ain’t me.
My concerns are different now so another guitar band wailing about how damn tough it is to be a teenager just doesn’t cut it. I just console myself with the thought, if you think life is tough now, just you damn wait, whinging little tykes. 
As i’m sure my parents thought too.
Speaking of teen angst bands, I was totally into the grunge scene at the time. Now that I’m older, I know that the reason it became “cool” to be a rebellious teenager in the early 90’s, is that teenagers as a group had more buying power then than at any time before.
I’ve since stopped looking at a band’s “image” which is a fiction concocted by fat sterno-drinking record executives in a boardroom.