Actually the masses of humans on planet Earth do understand the logic of "it's just our religion.." as intellectually non-satisfying as that may sound. The more you try to justify, intellectualise, and insert logic into this act the more circumcision will seem arbitrary. Havent you noticed that worldwide, the many cultures that practise circumcision (eg. Muslims, Australian Aboriginals, various African tribal groups and so on) aren't rushing to explain or justify it? Why does Jewish circumcision have to be any different to them?
Police disperse hundreds in brawl in Kafr Manda, northern Israel (Haaretz)