While I won't say that a speaker that doesn't sound great on all types of music is a bad speaker, I certainly maintain that the best speakers I have heard excell at ALL types of music. A bad recording is still a bad recording, but a speaker that makes a bad recording sound good in one genre, and a good recording sound bad in another, is just not something I am willing to live with, especially now when there are so many INCREDIBLE speakers that sound fantastic with all genres for so little money.
At this point in the industry, if you are spending over $2000 on speakers, they should sound incredible with ALL types of music, have a full range response (I mean that, using a frequency limited monitor in this price range is simply losing out. Bass problems can be fixed with proper acoustic treatment, no matter how bad the room is, and music happens down to 20Hz, whether there is a drum or just a soprano. Any speaker at this price should be comfortable at around 30Hz) and offer superior dynamics, imaging, and aesthetics.
I just don't think you have accept anything less these days.