Someone, definitionally, owns all the privately held land in the US. Large landowners in rural areas are on average more politically connected and wield more political power in their communities.
Telling them that any sort of work on their own land—no matter how small—requires extensive oversight might be well-intentioned but pisses off a lot of people who will then become bitter opponents of even well-designed environmental legislation. Telling them they should have made better purchasing decisions just motivates them even further.
What actually ends up happening is these people then do it anyway with zero oversight, because the amount of land involved is too vast to enforce these things on. You also get large concerted efforts to overturn any and all environmental protection.
I didn't say they can't do anything with their land, but if you live on land with beavers you should know how beavers and beaver dams work so you don't do something stupid, like building a structure in the flood path of a stream or river full of beavers, or killing the beavers so that you can and then complaining about the beavers coming back.
Complaining about how beavers work and what beavers are doing on your land is the same as building on a historic floodplain and then complaining about it flooding. Or building in hurricane territory and complaining about hurricanes. Or building in the woods and complaining about deer eating your plants and trees falling on your driveway. One person's lack of foresight is not and should not be everybody and everything else's problem.
Do your research before you buy things. Only an asshole buys and/or builds next to an area with long established feature X and then complains about feature X existing and how its "unfair" they can't have it taken down or destroyed at will.
I agree with this kind of oversight. But as someone with a friend who is both an environmentalist and does own land adjacent to a river and land managed by the national forest service, the latitude for what you can actually do without serious oversight is essentially nothing. Luckily what he wants to do is essentially nothing, but even the very minimal bits he does want to do—which includes making fire breaks in a populated area which is wildfire-prone—is questionable.
It’s been eye opening to see the lengths he’s had to go to in order to stay on the right side of things. And it’s given me a decent perspective on the burden it puts on even those who want do to be responsible landowners.
It’s also been interesting to learn about the perverse incentives it does put on those who own this kind of land. One example is that new paths generally can’t be cleared, except when a wildfire happens, if you can justify it as part of firefighting or fire prevention efforts. So if and when there is a fire nearby, bulldozers come out in droves. I’ll leave you to connect that to what might be the root cause of some of these fires.