...and this applies more than 200 years later because... you say so?
It applies because it's logical. The logic of personal privacy and the choice of how much money you wish to give the government (yes you give it to them, not the other way around) does not change any more than the inalienable rights. In fact, it's part of our inalienable right to privacy. These tenets are a priori, not inventions of man. Taking money (read that as life) away from a man at the point of a gun is just as wrong today as it was 200 years ago. Why is this so hard for people to understand.
What is your evidence that people are more willing to remit taxes just out of the goodness of their hearts today?
You sound like someone advocating communism -- "everyone will work for the state and the state will give you what you need -- and it will work because everyone is so nice to each other." We know better. Communism failed everytime it has been tried because people are not willing to give economic wealth up for the good of the state. And now you want to try that system here.
In fact, your plan sounds like the way the UN is funded. Each country is supposed to remit a certain amount, but even the U.S. has withheld money for the UN when it has disagreed with the way it is spent.