Most archaelogists are public employees or employed by institutions dependent on public funds. This makes them more inclined to state intervention than the average citizen. Their paychecks literally depend on it.
> As a former archaeologist, we really don't care about random contextless artifacts.
Collectors do still value random artifacts, but a collection is much more valuable in context. A company that found such a site and could exploit it would be wise to hire archaeologists to improve the value of their property. You can sell the Crown Jewels for more than you can sell the individual jewels.
I don't intend to be dismissive in saying this, but the arguments that you're making are wildly off-base about the underlying subject. Moreover, archaeology for the sole purpose of increasing commercial value violates strong ethical norms.
Unless they weren't. Then they'd be blown up anyway, except we'd perceive a moral right for them to do so, and it would be harder to fight back against the practice.
The natives of that land would probably be deprived of their exclusive access, and private buyers could hide their own collections from the world. But most public buyers and many private ones would be very motivated to share these precious items with the world, scientifically and culturally. The publicity increases their resale value if nothing else.
How many ancient artifacts are hidden away because they are illegal to own? I might or might not have owned such an arrowhead once. If I did and still did that could make it something I had to hide. The pool of artifacts available to archaeologists and museums may well be smaller due to such perverse incentives.
I know people who make home displays of arrowheads and potshards they've found. But others, not wanting to openly break federal law, keep them hidden in drawers. The law effectively hides away evidence of the ancient people that came before us. If they removed the threat we could openly celebrate them instead.
The artifacts that were destroyed were priceless. If they had prices, they probably would be high, and so would be carefully preserved instead.