Do you guys really think it's "holes on the beach" that would be the matter to bring-about-a "no-detecting" rule on this beach ? Heck, I bet I could singlehandedly get that beach shut down and put off limits to detecting, all from the comfort of my living room here in CA.
All I'd have to do is make phone calls, send letters or email etc.... asking "can I metal detect?". If they say "yes", I say "is it ok if I dig holes?". They might say "as long as you fill them". Then I ask: "what if I find something of historic cultural value? Can I take it home for my own fun and profit?" At this point they might start getting a little queezy, and say "you have to turn that in". Then I debate them and ask "how is that defined of what is an 'artifact' versus what is 'ho-hum' ?" . And then I can say "what if I accidentally find indian bones?". And if, after all that, they still say "you have our blessing to detect", I tell them "please put that in writing signed by someone high ranking there (like the staff archaeologist, perhaps. Hey, you can't be too safe, right ?).
And I bet in the space of a day or two, without ever having gone there, I could get that beach shut down. Oh sure, they'd probably say "no because of holes" (in which case we say "durned those guys who must've left holes"). But notice that's only the "go-to" reason for the "no" they just gave you. Or they can say "no because of cultural heritage". In which case we say "durned those archies" . But did you really ever think an archie was just "happen to be passing by, and decided 'gee let's make a rule about this' because he saw an md'r ? Probably not.
In all the above scenarios, it's always traced back to the "pressing issue" of the "subject of md'ing" getting put past bored pencil pushers and archies. And was never that anyone left holes (on the beach anyhow), or cultural heritage concerns. Those are only the "go-to" reasons, they use to justify the rules they just invented. The REAL reason was/is md'rs who go making themselves a giant red-bullseye in need of those bored pencil pushers sanctions and permissions.
Moral of the story ? Don't ask silly questions, and let them continue to think of us an innocuous geeks finding modern clad.