It would make sense that if you needed to collect tax, you would encourage activities that created in real economic expansion (investment, which leads to business and job creation, innovation, etc) and avoid taxing that to death.

What I don't understand is how some folks feel we need to tax people just to keep them from becoming too rich. Maybe governments should just instead tax with the aim of collecting revenues to do the business of governing instead of trying to become its own business (something that has been proven over and over it sucks at and doesn't do nearly as well as real businesses?).