One of dozens of variables that can be used to build good speaker... undoubtedly doing this has a negative effect on something else. Audio design is all about trade offs.
Well said. I think with the improvement in driver technology and materials the compromises of 1st-order crossovers has been largely mitigated, but there are always trade-offs. I had Thiel CS1.6es in my system for a while, and I do think there is a certain “rightness” about a well-implemented time/phase coherent design, but that said I hear a lot of the same properties from the likes of Joseph Audio so pick your flavor. All else being equal, which is NEVER the case, I’d take time and phase coherency, but only IF the rest of the sound profile meets with my overall tastes.