Using the language of another group creates a tacit connection to that group in the minds of everyone involved. That may sound obvious, but it's pretty powerful. If, from the very beginning, we referred to ourselves as "avocational archaeologists," I strongly believe that we would be in a different place with them, even if we did exactly the same things we've always done.
From now on, I'm an avocational archaeologist. It's going on my introduction "business" card that's handed out to property owners whose yards I want to search.