The answer to this actually is really simple. Once one sets aside their immature demand to always have what they want, realize we all live together in a cooperative society, and cooperate, this is a no-brainer. More on that in a moment.
The concern about a dictatorial state, rules that are simply for the sake of power, blind enforcement of rules, and on and on, are all very legitimate complaints. I'll be among the first to say our society has gone too far with drones, heck, too far in pretty much all domains of life. WAY too far. That said...
This is not one of those cases. The purpose here is clear: To preserve the beauty and peaceful enjoyment of a public monument for the enjoyment of all. It is also abundantly obvious to all but the near clinically insanely antisocial that drones buzzing around the Arch would clearly disturb this entirely reasonable public goal at a public venue.
As such, all this discussion/argument over airspace, the ground, who controls what, etc. is little more than arguing over how many angels can dance on the head of a pin. It's beside the point. And because it's beside the point, the law will adapt to more closely match "the point" going forward. The best way to hasten that change is to behave as if you don't get "the point" here, and play games like are being discussed -- launch outside the park, buzz the Arch to your heart's content, land outside the park.
Guess what? The Arch will become an NFZ (if it isn't already). Count on it. If you think instead a law will be passed protecting drone access to the arch and punishing tourists, you really are insane
And that, my friends, is THE POINT, in general, not just in this case. We share this space, and we all are equally important. We have to accommodate each other. When someone ignores your interests entirely, guess what? You're not going to pay much heed to theirs. This is what's happening with drones as we speak (and fly).
Be aware of the reasons behind restrictions, not just the restriction. Armed with that, seek permission to do what you want to do -- that's how we all "play together". Almost always you'll be able to get that permission, with some constraints, which is how we all accommodate each other.
And sometimes the answer simply is "no", in which case you move on. No one gets everything they want.