I'm not a fan of Bezos or the other "fuckers", but how are American billionaires going to pay that tax? They'll have to sell assets to someone not subject to the tax, probably a billionaire from another country.
Do you really imagine anything will get better when most big American businesses are owned by foreign billionaires? Will working conditions in Amazon warehouses improve if Amazon becomes a subsidiary of Alibaba?
Or you could tax the assets themselves, in which case it no longer matters who owns them. And seeing as how certain assets - like land - have inelastic supply (i.e. taxation doesn't affect the price point set by supply v. demand) and can't exactly be moved to offshore accounts, taxing the value of those assets would be far more economically sound than the current emphasis on income and payroll taxes.
100% agree, so lets tax the fucker, and all the other fuckers.