You'd better ask JulieAnn42. It's one of those fallacious reasons that get dragged up to justify male circumcision.
She has expressed her feeling, as she has a right, and it has been further discussed, which is also right - now, let's get down to the question cut and uncut.
For instance, some guy were not cut correctly and end up bent (still very functional but bent) how does that affect screwing? And if an uncut guy really has a lot of foreskin where you can hardly see the head - how does that affect screwing?