Well yeah. Or probably even more importantly, a tax that most people wouldn't be paying. Efficient taxes tend to 1) be broad based and 2) be very hard to avoid

Well yeah. Or probably even more importantly, a tax that most people wouldn't be paying. Efficient taxes tend to 1) be broad based and 2) be very hard to avoid by changing behaviour. And that means they will impact a lot of voters, and voters don't like paying taxes. :)