What you call morality is nothing more than an opinion.  When you boil it down moral relativism, which is what you describe, is simply an opinion masquerading as morality.  We are no more free to choose our own morals than we are free to choose whether the sun is going to come up in the east.  The mess we are in right now is the result of the progressive idea of subjective and arbitrary assumption of morality based on some fuzzy notion of "fairness."

The whole idea of progressive taxation is as counter to the fundamental principle of our Constitution as it can be.  The idea expressed over and over in our founding documents is that all men are created equal before the law.  Progressive tax policy is a direct insult to that entire proposition.

We are not free to choose the morality that is convenient to us.  We can choose whether we conduct ourselves in a moral manner in accordance with the standard laid out by our Creator but we can not choose the standard.