-- But both you and Sox are on the same side in arguing that there is a public duty of each person producing at a maximum level. --
Not at all. I don't think bad of you because you don't contribute. The same way I don't think bad about illegal immigrant who crosses the border. But at the same time I want tougher immigrations laws.
In no way do I advocate everyone to contribute at a maximum level. What I do want is to preserve the system that encourages those who WANT to contribute at a maximum level. Which all comes to the taxaction and redistribution. I think if taxes go beyond 40-45% the motivation decreases. And even more if those taxes are redistributed to those who don't contribute - the motivation to work hard not only decreases, but more and more people might decide to became the recipients of those redistributions instead of the donors. And such system eventually stops working. So I am for such system that separates those who contribute from those who don't. Which means they have different lifestyles and as some say belong to different classes. This encourages people to move to upper classes. I have no problem if those who make more money pay more taxes. But I am against direct redistribution: like paying for health insurance or increasing minimum wage to absurd levels.
It has nothing to do with the government services you do use but what are the government services that our country needs. And it is not just income but what is the IRS collecting to pay for those needs.
As for marginal utility - if our whole country were like you then our whole society would change as well as our economy. We are currently build around a consumption economy. Our capitalist would not like that changing.