Why Aren't More Speaker Designers Building Augmented Widebanders?

Over the years I've owned a number of different speakers - KLH, Cerwin Vega, Polk, Opera Audio, Ars Aures, and Merlin VSM. One thing they all had in common was a crossover point in the 2000 hz (+ or -) range. I've read reviews of speakers where the reviewer claimed to be able to hear the crossover point, manifested as some sort of discontinuity. I've never heard that. My Merlin VSM's for example sounded completely seamless. Yet my new Bache Audio Metro 001 speakers, with a single wideband driver covering the range of 400 hz to 10,000 hz, augmented by a woofer and a super tweeter, sounds different from all of these other speakers. The midrange of the Bache 001's is cleaner, more coherent, more natural than I have heard before. Music flows from the speakers in a more relaxed manner, and subjectively dynamic range is greater, with no etch or brightness, and no loss of resolution compared with the Merlins. I have to conclude that Bache's design has an inherent advantage over more traditional designs with a crossover point or points in the midrange frequencies. I wonder why more speaker designers haven't tried this approach?
Thoughtful, well written post from Teo_Audio.  However at least one company - Zu Audio has made augmented wideband speakers enough of a "pull" product to be successful.  
Don’t forget about the Vaughn loudspeakers using widebanders with plasma tweeters coming in about 5k.
I haven’t ever heard them myself but I’ve talked to many around our country that have,and they definitely have my interest peaked.

I get the theoretical appeal of a speaker using a wideband driver - theoretical coherency and all that.

But in practice, I don't really find speakers divide up that way in terms of coherence.   I find plenty of 2, 3, 4-way speakers to be quite coherent.

For instance, a couple of Thiel models I own as as coherent in the mids/treble and down as any speaker of my acquaintance.  I can come beck home from listening to tracks on my pal's electrostatic speaker and hear no loss of coherence through my speakers.

(And I went from Quad ESL 63s to Von Schweikert box speakers and heard virtually no loss in coherency).

If anybody who interested to listen widebands drivers coherence in different configuration just welcome in Brooklyn listening room