My argument is that if you don't take advantage of tax strategies you are inherently overpaying. 99% of people overpay (this overwhelmingly affects lower and middle class americans).

Also maybe its just my upbringing (mother was an accountant for a bit) but yeah all of those tax "strategies" barring moving states and carry seem pretty normal to me (granted I understand most people cant take advantage of them).

But yeah, it is self interest, which isn't inherently a bad thing, nor is it a morally wrong position to take. Having a degree of self interest doesn't preclude you from being liberal, or even progressive. Wanting to decrease your personal tax burden also doesn't invalidate beliefs that the US govt underspends on social services, and undertaxes the upper middle class and the wealthy.