This is a good question and I think the best loudspeaker should have both good measurements and good sound but the problem is most of the time the way designers choose to have better measurements is not the best way for human hearing system.
I am not audio designer so I can not introduce you much more information but I have a simple example. Imagine we need fast and low distortion amplifier, we have two ways to decrease distortion :
1- using better high quality low THD parts
2- using negative feedback
The second way is very effective but not ok for human hearing system.
The first way is depends on limits of parts and needs higher costs.
Now the designer decide how to solve the problem.
I think between modern speakers Gobel Majestic is a good example of perfect balance between dynamics, musicality and measurements.
