Does bewiring decrease "wholeness" ?

Are you sure the sales guy was talking about bi-wiring, no bi-amping?

Bi-wiring is a personal preference and system dependent. Not just speaker dependent.

In my experience, a better mono-wire has provided better overall sonics over lesser bi-wire where both versions cost about the same.

Remember that you are paying for the extra wiring and terminations. Sometimes you can get substantially better quality mono-wires for the same price.

Lastly, one should not feel that they must bi-wire simply because a salesperson or mfg'er suggests they do. Not saying that's why you are, but I just thought I'd mention it.

-IMO

Herewith this modest proposal: Get a friend and a blindfold and try them both ways, without your knowing which way is which, with a cd you've heard at least a hundred times. Can you hear a difference? If so,wire them the more desirable way.

I have felt at times "Biamping" seemed to distract from the sound but not biwiring.

Thanks for your comments.
Your suggestion IMO, that the salesman as an interest in his suggestion is not correct, since he was complimenting the single wired option (with jumpers) over the biwered option.
I am also aware that, bi-amping was once evaluated by a revewer with the specific set-up he was working on, as increasing some aspect of the sound being reproduced but with a slight decrease in the "realness" or "directness" or "wholsomeness" of the musical event.
The salesman was basically suggesting that for him to be-wired was conductive to give the type of result that I have tried (excuse my french) to describe above.
I had never read or heard about it before, but this audiophile-salesman was definitelly using a single run and jumpers on his speaker set-up at home.