the foreskin is the same type of skin which makes are eyelids, sensitive and serves the same function to keep a body part protected which includes keeping it soft and moist. Get a book on biology dude
typical America response, you have seen few if any natural cocks and you think a foreskin is something alien. Nature gave us perfect bodies, all the parts have a function and all parts are beautiful.
I'll finish your sentence "to make sex less appealing, to deform the shape of the glans, to leave scar tissue which never goes away, to make sex less pleasurable for your partners."