They are the only ones who can afford it. The ancient slogan of the socialists has been that nature is wholly abundant, but artificial human institutions and economic arrangements thwart the operation of nature's bounty. Therefore, all we need to do is tear down the artificial barriers to wealth. This was the vision of Marx and Engels, and it is alive and well in every society on earth, in spite of the fact that it is not always associated with Marx and Engels. The premise is fallacious.
Nature has limited capabilities for production.
If we have learned nothing else from the ecology movement, we should have learned this. It is man, with his wonderful gift of reason, which makes nature flourish. It takes an expenditure of energy, capital, and time to make nature give up her fruits for the purposes of mankind. Economic goods are scarce, that is, at zero price there is greater demand for them than supply of them. Prices allow us to plan, evaluate our costs, make clear and responsible choices.