Uh, yeah, we definitely do. I have relatives who sell the oil under their property, and that absolutely is taxable income.
But your relatives didn't get a tax bill for 25% of the value of the oil the moment it was prospected, did they? Their land value went up but they weren’t taxed on the value increase either (that happens when the land is sold).
Generally though, you also don't pay property taxes on securities (property tax is a pretty specific tax and a unit of crypto currency doesn't directly translate). I don't have any apropos objection to a property tax on crypto at the moment mostly because that's not the point being discussed. We just don't do it currently. The more appropriate analogy would be like you have barrels out and oil rained from the sky. Now you have some barrels of oil. Your land value doesn't increase, but also you don't get taxed because you collected oil from the sky. You get taxed when you sell the oil. Maybe we do need a tax on the latent potential of your property to generate crypto, or that information should be factored into property value, but again that's not quite what we're discussing.
The IRS considers found gold to be gross income and taxes are owed on it.
Why shouldn't we? We tax people on the FMV of something valuable created out of thin air, why should gold be an exception?
There are income taxes which apply when goods or services are sold.
There are sales taxes when goods are purchased.
There are property taxes when goods are owned.
Nothing gets taxed on creation.
For example, on gasoline. The tax occurs at the pump, not at the refinery.
"An excise, or excise tax, is any duty on manufactured goods that is normally levied at the moment of manufacture for internal consumption rather than at sale."
I'm very familiar with how the excise tax on alcohol works, it's definitely a tax on creation not consumption.