In the US about twenty years ago, there was a minor movement for a flat sales tax that would replace all other taxes. I lived in Georgia at the time, which was the epicenter of support for the idea. Proponents got themselves stuck in a metaphoric tarpit when they wouldn't accept that most people's way of calculating sales tax was different than what they promoted. At least in the US, if there's a 7% sales tax, it means if you buy something for a dollar, you pay seven cents in tax. Their flat sales tax would have been 30% using this method, but they wanted to promote it as being only 23% since $0.30 is 23% of $1.30.
I'm sure there were other reasons why it failed, but for the people I knew who supported it, claiming it to be a 23% sales tax instead of a 30% sales tax was a hill they were willing to let the whole thing die on (and it did die). Lots of people who casually supported it at first when they heard 23%, lost interest when it was clarified what that really meant. The difference between 23% and 30% isn't all that great but if you're going to overhaul the tax system, trust in those who are doing it is needed.
I'm sure there were other reasons why it failed, but for the people I knew who supported it, claiming it to be a 23% sales tax instead of a 30% sales tax was a hill they were willing to let the whole thing die on (and it did die). Lots of people who casually supported it at first when they heard 23%, lost interest when it was clarified what that really meant. The difference between 23% and 30% isn't all that great but if you're going to overhaul the tax system, trust in those who are doing it is needed.