If you earned the money legally, you can buy a rock in the ocean. Owning land isn't theft, and no one's entitled to someone else's beach just because it's big.
Plus private owners often preserve spots better than public mismanagement does.
Agree, and add: secure property rights spur division of labor and investment, but laws should curb land hoarding that blocks others from productive use.
Taxes should reward work and invention, not possession of land. Taxing islands stifles curiosity and the common good.