> Avoiding taxes is not unethical in itself, or do you also denounce people who claim any tax deductions?

False equivalence. You can deduce anything that's used to generate the profit. This makes sense.

> The question is: why is the US entitled to these taxes, such that avoiding them becomes unethical?

The answer to this question is the same as the answer to the question "why is the US entitled to taxes".

You can generally also deduct charity payments to your own "land conservation" charity, which can then go ahead and buy 50 acres of land around your recently built mansion.

Pretty sure you wouldn't consider that one one that makes sense.

Plenty of deductions exist for a reason, and generating profits isn't always one of them.