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

In the manual for my new (to me) Vandersteen 2Ci speakers, their recommended version of (vertical) bi-amping is using two stereo amplifiers each driving one speaker with the left output driving the tweeter/midrange and the right connected to the bass. Maybe this is common but I'd not seen this sort of configuration before.

"Hypocrisy"

Kalali, You can go to the Ask Ricard part of their site and ask your question there. I have heard it set up this way with NAD amps as well as Belles amps and boy does it make a nice difference.  You can really get a lot of high end sound out of those 2Ci's.  I've heard them run with my Ayre AX5/20 integrated and it really showed off what they can do.  There is a reason it's the best selling speaker of all time for the high end.  Fanboy here, lol.

@kalali 
The benefit of doing that is the speaker cables are kept shortest, while one channel will be a lot more demanded that the other one just because of power draw for each band.

Alternatively, using the same two stereo amps, one for L and R bass and the other for the top will give a balanced draw for both channels at each amp at the expense of longer speaker cables.

Level matching amps from the same manufacturer.... No that is completely contrary to what I am trying to achieve. I want to have control of the treble and bass separate from each other. I don’t always agree with mastering engineer decisions on how the record should sound. In those cases where I feel treble is out of control or bass is severely lacking , I want to be able to use tone control and volume separately for Treble and Bass. So when particular recording or my own speakers don’t deliver desired tonal balance to my ear I will intervene and adjust to my liking.
On a side note; I have heard that tone controls are frown upon by purists, but to my logic : why spend thousands upon thousands on your gear and listen to someone else idea of the music instead of adjusting it every time to your particular liking?