I work in the film industry over 20 years and there are a lot of reasons why no one makes decent music vids anymore. The first one being the cost. There aren't that many people in the world these days who are willing to invest a million or more dollars in something that doesn't bring back a profit. Music vids by definition, are really advertisements. Regardless of what you may think of them or their music personally, no one understood that better than people like Michael Jackson, David Lee Roth, or Madonna. who used their own cash to produce the 3 -10 minute vids that are still recognized today as film events. The idea was to use the skills of the artists and crafts people who normally would work on theatrical films, to create a thing that ultimately would be something that promoted their music.
It's not that difficult to say that David Lee Roth's success as a solo musician was largely due to the appeal of his special brand of film production. Mr Roth was a guy who never took himself too seriously and he was able to inject that attitude into his productions and that's what made them funny. People tend to remember the things that make them laugh so it was very clever what he did. Its not like the music was all that great was it?
I haven't watched a single minute of TV in over 10 years, but I do recall around 1994 or so spending an afternoon at a friend's house where the MTV was on 24/7 and every time I would look up I saw something that I would describe as a low budget commercial. That ranks way below a low budget films....
But that's what they had become. You had a group of people in the film industry who began to 'specialize' in music video production, and people in music industry who would exclusively use them which explains why so many of the bad ones, and they are the majority, look the same...
And the music wasn't all that great either was it?