It's all in the (fish)eye of the beholder.

Everybody is just trying to look cool. Everybody probably looks like a "poser" to someone else. And in a cruel twist of irony, the inventors and early adopters of some "cool" new thing, look derivative and boring years AFTER everyone else has done it. Kids don't have a long memory for these kinds of things; they grew up in a world where it was already old news and boring, never having experienced a world without it. This shift in perception can happen sometimes even among people old enough to have been there at the beginning. So yeah, they are just a bunch of posers trying to look cool, but aren't we all?

Hate to be the bearer of bad news, but with the music it also looks that way to someone over twenty years old or so.

It was a remarkably stupid time, however even back then there were better music videos. E.g. stuff by Michel Gondry, Run Wrake, or Spike Jonze.

Late 90s in a nutshell, to be honest.