There is also a more serious side to the answer!
in 3rd world countries you could be mistaken for a mercenary soldier and shot on sight!
another side is if you're on your own and collapse in a bush , no ones gonna find you!
(devils advocate would say well would you get found anyway!)
aside from the fashion issue, most that use camo wear parts of it as you say to get some effect.
it's far more acceptable to walk into town with combat trousers on or just the top but both as spamel says
you look like a Johnny Rambo type
we had years of problems convincing people that survival was ok and not a wierd thing Camo just seemed to get in the way sometimes portraying some as SAS wannabes, or special forces eliteist.
i uesd to wear Full camo years ago and i did get people ask if i wanted to be in the SAS! though i liked the gear i didn't like the image i was sending out!
that's not what Bushcraft is about....there are some crossovers with survival, but we want to keep the good image not the iffy one!
(by "iffy" i mean potential to misunderstand or misrepresent!)