Totally agree- Being a nudist I cannot think of ever having had an erection at a nudist resort.
To me eroticism starts in the mind, with imaginative thoughts, hints rather than statements, seductive dressing opens the mind to fantasies.
The actions of the naked party however plays equally an important role. A nude person just walking about would do little to interest me as such. Their body language would be important, light physical contact would most likely be mind-blowingly seductive.
I have seen plenty of naked pussy in my lifetime, both in work related circumstances and in my private sphere, believe me, there is nothing at all sexy about a naked pussy when you are dealing with it on a professional level, so I must agree with your statement totally.