While I understand the need for archeology, the sad fact is that the vast majority of the stuff the archies find goes into a box in storage never to be seen again, except to be pilfered as happened in the great Wisconsin State Historical Society thefts some time ago. The found items in a box are actually a public burden, since they have to be stored forever.
Not only that, there is only so much knowledge you can get out of a site, most of it not exclusive. Well, someone lived here, and here's what he ate, and he lost a 1889 dime. Yawn. It just cost the public $60,000 to find that out.
Even when they do salvage archeology, only a small fraction of the site is recovered, and they delude themselves into thinking that they can infer something from the 1% they dig up, the rest remaining in the ground, or worse, destroyed by construction.
Bottom line: Greed is greed, whether ours or theirs. It's just that they can enforce theirs.