If bi-amping is so great, why do some high end speakers not support it?

ctsooner, the only scientific logic I can intuitively understand about the benefits of bi-wiring is the reduction in the cable resistance by doubling the length of the cables. The downside being the proportional increase in the cable capacitance, inductance, etc. The net effect could of course yield improvement in the SQ. Do you know what other design considerations might be in play that could further strengthen the argument for bi-wiring?

Dick Vandersteen has a white paper on biwiring posted somewhere

I go bi-amp tho

Yes, Vandersteen has a white paper.  He was sharing at Audio Connections during one of his visits.  I've spoken very recently with him about bi wiring and I can't share what he said, because I honestly don't remember it, lol.  I do however remember his saying something about the powered speakers don't benefit quite as much as the non powered speakers.  Something about the bass.  I'll try to find out what I can when I'm able to.  

It's a very interesting debate, but honestly, if a designer has designed their speakers to be bi wired and or bi amped, then I don't see how we can say they are wrong.  The bi amping basically is to help with the bass control and that in turn will also free up the upper amp to deal with the speed and control of the mid and lower any problems you may have with dynamics.  It would make sense that is what he's doing with using powered subs in the Quatro on up.  I just switched from Treo to Quatro and it's not just the bass that is better (especially with the 11 band room eq), but everything is so much better.  JMHO

Bi-amping with tone controls using vintage amps, that is where it is at. For around 800USD one can have two Ymaha Class A amps or Luxman Class A running their system. You can adjust treble, mids and bass to get the best out of recording. My speakers are always lacking in bass on Jazz or Hard Rock. One touch of tone control and the bass comes out...
I recently bought wide buffle speakers from Pioneer that are capable of tri-amping (not that I am gonna do it) but just to show that the ideas are very old as Pioneers are from 1970s. I'm lately became drawn to wide baffle sound (JBL, Wilson, Devore) and really come to dislike thin sound of the narrow baffle speakers.

ctsooner - I'll rephrase your comments a bit:

if a renowned audio engineer and speaker designer has designed their speakers to be bi wired and or bi amped, then it is very wise for a consumer to follow their directions

Dick V. is highly respected and has been working towards maximizing SQ in his given designs for decades - it took me months of careful listening for hours every day to decide to move from Vandies to Maggies (and I understand if others make the opposite move)