Originally Posted by why
It's like this: 1. Man wears a shirt to go hunting and notices the shoulder is torn 2. Man sees need to reinforce his shooting shoulder 3. Man reinforces the shooting shoulder with a leather patch 4. The hunting shirt is born So the hunting shirt is basically...a shirt with an added patch to make it more accomodating for hunting. Take off the patch and you've got a shirt. Now with boat shoes: 1. Man wears loafers on boat 2. Man notices it's difficult to get in and out of loafers on boat 3. Man has special shoes made with a different lacing style to get his wet feet in and out of the shoes quickly 4. The boat shoe is born So the boat shoe is...a loafer with a different lacing style. Both have non-aesthetic functional elements that I don't think are pervasive enough to not look odd in mainstream culture. They don't necessarily add anything to the clothing they're on besides a functional element. When that functional element is no longer needed, there's really no reason for it to be worn.
Boat shoes have nothing to do with ease of getting on and off since the point is to actually wear them on the boat... the difference if you actually care lies in the sole which typically is non-marking razor cut (the wavy cut marks on the bottom of your shoes) so as to provide traction on a wet boat deck. eg. of a laceless boat shoe- http://www.boatersworld.com/product/185241890msk.htm
I don't ascribe to your philosophy that a function of a garment that you are not utilizing somehow revokes that piece of clothing's reason for being worn. Sometimes it just looks cool and it having a detail that actually has a historical function adds authenticity that I for one enjoy.