Mrf. I have a couple of serious quibbles with this, in a friendly sort of way.

What about a priest/ess whose work is solely to serve the gods? Such priest/esses don't need to live apart or wear distinctive clothing, nor do they need to serve as signposts for other humans. Some of them do so, but it's a matter of their personal vocation rather than any external definition of their role. I say that from direct personal knowledge because I'm one of them myself. Some of us are there to *be* the edge: not to point to it but to participate in its manifestation. Some of us are there to be a hollow reed for the gods.

Also in the Rosicrucian tradition, which has been participated in by a good many clergy down through the years, one is specifically enjoined to wear the clothing habitual to the country in which you dwell, and to avoid distinguishing yourself from others by unusual dress or behavior. (I'm being a bit of a devil's advocate here, but I'm also a participant in that tradition, although not in a priestly context.)

So although I think you have a very good point about certain types of priest/ess, I don't think it's true of all of us or of all religions.