1. Are we sure that we just aren't just paying more attention to the bad stuff? I'm sure if we went back in time to the 80s or so we would find a crapton of terrible music and movies. We see the good stuff from the 80s and wonder why there aren't more good movies nowadays, not realizing that we either forget, ignore, or missed the bad stuff.
2. It's possible that it has something to do with more mediums being around nowadays. There was television, there were movies, there was talk radio, and there was music. Compare it to now.
The number of television channels has skyrocketed, so the individual channels have stiffer competition. They can't take as many big risks with there shows, so you might get one good new show a year.
For movies, I hate to say this, but the stars are gone. Aside from Johnny Depp, no one can guarantee that seats get filled. Look at the action movies, who are the big name action stars that appear in franchise after franchise? You have Depp(is the action-comedian), somehow Channing Tatum, Robert Downey Jr (who I admit is doing well), I think the guy who plays Thor, Chris Hemsworth (who I had to look up the name of), might become the must have action star if he gets a good movie. And let's be fair, the average comedy has always played to the least common denominator. I don't do romances, so I can't speak to that front. But the end result is that movies have to play it safe
Radio has mostly disappeared, though, so -1 medium.
The music industry is actually hurting, so safe, generic, and vapid music is kinda necessary to keep companies from going under. And no one is going to spearhead a change of pace under their conditions.
Video Games have started to rival the big industires. They had their time of rapid expansion and development. Look how fast they progressed, and how quickly new genres sprang up. How long did it take television to do that same amount of development? There problem is that it is so much harder to build a game from the ground up then a movie, so once a company gets a solid franchise, that franchise has to pay for all the other projects the studio undertakes. Some of them do well, some bomb. Some are new and innovative, some are just retreading the same ground. I think bad video game industry has been overblown just a bit, though it definitely got really corrupt really fast, or just plain lazy. You choose.
Now for the internet, the Ultimate Contender of Mediums. That place where you can go to watch movies, television shows, listen to music, and download games, all for free. Now I love the internet, but the fact that it can compete on nearly all levels with nearly every medium is hurting entertainment in general. It means the mediums that have to pay for crap have to compete with something that will just show off old, successful stuff since it doesn't need to sustain itself. And the old guard can't just show off old victories and hope they can stay afloat that way.
Personally, I like having hard copies. I don't have an e-reader. I'm a console gamer. I buy Blu-Ray discs, Dungeons and Dragons hardcover books, even CDs. I don't buy Steam Games, download music (like I-Tunes) or PDFs. And I'm a poor college student. If I want it, I save up for it and get it in the most concrete fashion I can, but I know most people aren't as vehemently against downloading things as I am. Like my friends. Even taking into account cheap prices like Steam Sales, the worth of the games, music, movies, etc that they download is around ten times as much as they actually pay for entertainment, and the objects they do buy are nondigital, like magic the gathering cards. Their digital library is essentially free. I know my friends and I are the two extreme ends of the spectrum, but I feel like most tech savvy people, a constantly increasing percentage, lean more towards my friends end of the spectrum than the middle.