Rarely do they invent new law and policy to do something when an existing law covers it. Why declare you don't own the air when they can just as easily say you do? As you note, it's not like you can do anything about it, and if you claim a $0.10 toll per craft, the government can claim it's an easement just like the power lines above and below my property right now. Calling my ownership core to sky, with easements on both is quicker, easier, and consistent with all current laws. So why invent a new legal status for airspace?