Men have egos, and our egos are directly linked to our dicks for the most part. Circumcised men will argue that they can last longer, or are less likely to get STD because of a lack of foreskin. Uncircumcised men will claim they 'enjoy sex more' than their helmeted-soldier counterparts. The studies have had results on both sides of the spectrum in regards to feeling. I do believe that men lie during surveys and studies though. Guys will do anything to have their dick on a pedestal in contrast to other men. I can tell you though, from close friends who have been circumcised, most of them do complain from the lack of feeling from oral sex and actual intercourse. Not that I can check that (or want to check it out). Funny enough to add to my argument of egos and dicks, they always say the same thing: "I might not feel as much during sex, BUT... I can last longer..."
I do believe that circumcision is completely unnecessary though unless it is needed for a medical condition.
PS: Uncircumcised pipis foreskin pulls back when erected, so I dunno about this banana talk. Fuck potassium though.