Enough people can handle AR8 and 150BPM but find it boring because they like faster paced things. And why would you be bothered if someone else would play it as a something that's not a music game, none of your business how they enjoy their game right?
Personally I like to try out new maps in multiplayer with a bunch of friends and see how much fun they are with DT, but there's only a very limited amount of people that are willing to try 300+bpm for longer than 10 minutes. It gets really boring for some if you keep playing songs you can easily do, it's really not enjoyable at all to do stuff you can do.
I haven't seen what you consider the use of multiplayer, it's for having fun with others, right?