I think your closer to a plausible theory than perhaps some of the other responses.
Its important to realise even a speaker cable has finite impediance.
If you have a bunch of filters daisy chained in parrellel along that length of cable with their loads producing a back e.m.f then the farthest point on the cable with a filter is most likely to be a point that is modulated by the previous load along that length of cable.
By offering each load its own dedicated cable back the reference voltage source (zero ohms) then in theory there is less possibility of modulation of the other loads. Of course the whole idea falls over if the amp reacts to the back emf.
I should point out solid most amps with large amounts negative feedback have a low output impediance at low frequencies. They can however be influenced by load characteristics because of stability or what might be call transient response damping to reactive loads as a result of large negative feedabck ratios.
I am less convinced of the idea of seperate cables for corresponding frequencies unless you have the crossover filter at the amp end of the cable.
In reality I confess to using Zilch's cat 5 twisted ends cable to biwire my JBLs when I am too lazy to biamp.
Ian