Why Aren't More Speaker Designers Building Augmented Widebanders?

ive often wondered the same question.  in my car i have 3 way acitves that feature a 3" wideband driver made by hybrid audio technologies that is cspable of 200 to 18000 hz.  it does not sound its best running like that but it sounds amazing using it from 400hz to 5000hz which gives you the keat of the music in a single coherent point source.  it also allows the tweeter and woofer to run miles away from their break up frequencies and puts the crossover points where phase issues are easy to manage.  the system sounds clean, loud and spectacular and i would love to have a home audio speaker with similar approach.  
economics may play a factor because wide band drivers are typically lower sensitivity and multiple drivers may be needed in passive setups to prevent padding down the woofer and tweeter so heavily.  still quite feasible and desirable though, imho.  

Not many folks realize this, but you can stick a $50 wide band driver on a 48x60 inch piece of plywood (with just a hole cut for the driver) and get mind blowing good sound from a current source amp...and if you use the right driver you can get bass below 50hz that gives a smoother room response than a sealed sub.

Interesting idea seanheis1. I challenge everyone here to go out to the garage, grab 2 sheets of plywood and stand them on end in the corners of the rec room. Wait till the warden sees that!

https://hometheaterreview.com/bache-audio-metro-001-floorstanding-speaker-reviewed/

The review is of the standard pair.  Mine have upgraded cabinets (3/4" bamboo instead of mdf, and premium crossover parts including Audyn True Copper Max capacitors). 

The on-paper interrelated issues with widebanders is distortion (resonance), frequency deviation and dispersion. I don’t know Bache, but I do know Reference 3A and Horning Hybrid. Both lines use mechanically rolled of mid/woofer in to a tweeter that is connected to a capacitor. Subjectively I did not find either line to be a standard of mid-high frequency integration, although I like them both. The most coherent box speaker I know is Voxativ, although there is penalty with roll off over 10k as there is a widebander but not a separate tweeter. (The experience is well worth the rolloff, imo and probably the money as well). There are brands with more traditional crossover points like YG (1.75kHz), ATC (varies) and KEF (2.4kHz) that I think are extremely well executed. Vandersteen also does an awesome job in integration using quasi-widebanders with 1st order crossover with the tweeter point at 5kHz. The former three though have better dispersion, though. There is a lot of variety in execution, and it is fun to sample them. It would be cool if more companies like Reference 3a and Vandersteen would execute minimal crossover designs with carbon fiber drivers.