Agreed, trying to get the whole world to agree on a single tax rate (0 or otherwise) is unrealistic, and completely ignores the sovereignty of countries to design their tax system as they please. What needs to happen is a modernized way to calculate which percentage of global profits from each company are taxable in which country, and then leave it up to each country how to tax that (or not). The current system lets companies cook the books in a way where they can effectively relocate their profits to any country they want.