Why is Chinese pop music so terrible?

All pop music is terrible.

As one sci-fi writer once wrote, "99% of everything is crud."

20-30 years down the track, the ones that are still around become 'classics', the other 99% just fade away.

If you aren't familiar with a genre, you don't have the experience to tell you what's 'good' and what's 'bad', so you ascertain that it's ALL bad. You're normal.