Why isn’t more detail always better?

Hello,
I don't understand the question, actually. You ask if more detail would be less good?
But then there's the music, period. A system can be transparent, allowing the sound to appear as it should. If it doesn't sound good, it's not due to the "details" you hear better, but to the room you're listening to, and the materials you've chosen. 
The choice of recording quality is also very important. But a system that's transparent in the sense that it's balanced can't be bad.