Why Not Be Improvident

If a society as a whole fails to care for the welfare of its citizens what use is it? And if it deliberately damages their welfare, favoring some groups over others, it has lost its right to continue on as it is. 

Why should I try to be responsible, productive and decent when I'm forced to support a system that screws me? Why should I comply while politicians undo my best efforts and deprive me of my rights?

A sane society ensures some level of justice and motivates its citizens to live responsibly and well. It rewards citizens for living the way they should or at least doesn't reward those who only serve themselves.