Debate about bicycle physics on "wheels".

Hi,
I often hear, from a bike mechanical, we should avoid weight on rotary element on a bike, for better performances, he point mainly wheels.
He sais, weight on wheels is heavier cause wheels rotate.
I have no clue, for me the only thing that happends it’s your wheel pull more force on the center due to centrifuge, and that all.
I mean you have 1Kg wheel and 10Kg bike is the same as 2Kg wheel and 9Kg bike.

But i doubt, maybe there is something i’m missing ?
So is heavy wheels a myth or a reality ?