Well, but the complaint is "Bezos should pay his taxes". And we've now established that he has. So... To the comment you replied to's point: we should be upset at the tax code not at people who (as we've established) are probably following the law.
OK, a charitable reading is that two things are being said:
Bezos should pay a fair amount of taxes ie. we ought to close loopholes and raise the rates for billionaires
& 2. Bezos should pay a fair amount of taxes ie. by using legal loopholes and lobbying the govt. for lower taxes, he is acting immoraly and should stop doing so
Both of which I believe is what's meant but are harder to make into a pithy slogan
My point in my earlier comment is that I don't agree with #2. He pays what the government says his "fair share" of taxes are, and why would we expect him to pay any more than that? I bet every one of us here pays exactly what we owe in taxes and not a cent more. That includes taking tax deductions. Even if you take no deductions, you're given a free $13k deduction on your taxable income.
Obviously in some theoretical moral sense billionaires are underpaying. But what's the income level you need to cross before you should willfully avoid tax deductions and ways of avoiding taxes. Now codify that into the law in some way.