What exactly would that simple principle say?

That is already what government does – redistribution is the primary purpose of government. Hence why we have also seen the size of government grow pretty much constantly over the past decade.

If we actually want to target social ills themselves, we should consider targeting them, rather than broad loosely related principles!

But principles need not be complicated and it is principles that are too often not evident in the development of policy. A simple principle focused on inequality and redistribution would, in my humble opinion, go a long way to addressing the double sided coin called greed and envy that appears to drive so much social unrest. IMHO.