While I whole heartedly disagree with the practice of circumsizing babies. (babies can't consent therfore an unnecessary procedure is just flat out unethical) It's not really true to say science shows that the foreskin is erogenous or even that circumcision affects sexual pleasure.
There is a bit of conflicting data out there so there is still some debate over the fact but right now the data leans heavily toward there being little to no adverse affects on sexual pleasure. And in fact some anecdotal evidence actually seems to show that the opposite may be true; that circumsized penises may actually be more sensitive to sexual stimuli.
Again though, I can't stress enough how much I believe circumsicion is wrong.