Why do people think income tax is ok?
Because the slavery it's their dream. They wish to serve someone and receive some cookies for their hard work.

The most of the people unable to use own freedom properly, it's the reason why democracy won't work ever. Democracy is a myth, even more ridiculous than implementation of communism through the revolution.
By the way, there are many ways to resolve tax issue. The most of taxes could be replaced with voluntary investments, for example... Government is able to emit a special obligations for this purposes. It will help to fight corruption, because invested money are much harder to steal.