Hey, wow, that's a great way of looking at it. The actual "net outcome" type of thing. That if it had been a walmart proposed for that site, no one would have cared. They'd have hired the right, uh ... "customer friendly" archie to decide there's nothing of archaeological significance there. Presto, you can go ahead and build, eh? Conversely a "purist" archie (on someone else's payroll) will declare (and be cited in the news media info-babe blurbs) to say any other such scary stuff, and declare every seashell to be "culturally significant".
Gee, so let's all just go ask long enough, and hard enough, up the chain of command, and sure: you'll eventually find someone to tell you you can even hunt a modern city sandbox (and you'll be satisfied knowing it was a good thing you asked). Heck, even put that archie's quotes on md'ing forums, so everyone else will then now know that they too can't hunt that modern sandbox (afterall, you can't be too safe, eh?)
