So much time wasted with music videos!

I see what you're saying, but mostly disagree.
First, the music parts never reached 3-5 minutes, maybe 1-3 minutes, tops, and usually with a break in the middle somewhere with a joke. You could always hit fast forward or use the opportunity for a pissbreak, but then you'd miss the joke in the middle.
Second, they only ever focused on a music performance maybe 10 to 15 times in the entire series (roughly, not entirely sure, I'd have to double check) so it wasn't a constant issue.
Third, while I could do without a Michael Bolton or Clint Black performance for example, it was cool to see Butthole Surfers, or Wu-Tang, or Beck doing their thing. Point being, I can see where it would be annoying if you don't like the band in question, but when you're a fan then it was a nice bonus.
Forth, the show is more like 20 to 25 minutes per episode, including credits. I'm willing to bet if they cut the music parts, there wouldn't be more jokes in its place, the episode would simply be 1-3 minutes shorter that week.

I chiefly disagree too.

Often the music plays a part in the episode - not necessarily central. Sometimes they are just inconsequential and I can understand in that circumstance it can be pointless.

I thought the episode when Colin Hay appears is a perfect example of integrating the music.

"But tonight we should have fun, not dwell on Scott Baio."

I think it depends on if you like the band or not. If so, then its a nice bonus with a trip down 90's memory lane. If not, then it can be painful. I had to take 2 Tylenol during the episode with Porno For Pyros. There is not a proper adjective or verb to adequately describe how much they sucked.