Genuine question for those who think "tax is theft", where would our infrastructure come from if we weren't taxed? How would people who cannot work/don't earn enough to live be supported? How would sick people receive medical care? How would our roads be maintained? Our police force funded? Hospitals built?
I was being a bit tongue-in-cheek with that phrase, but to answer one question seriously...
There was an article in the Guardian recently putting your side of this argument, and I actually agreed with much of it, for example I disagree with the right-wing idea that high rates of tax discourage economic activity. However the author then went on to say that the "taxation is theft" idea was wrong, the money you earn is not yours in the first place, it belongs to society, as the wealth of the rich could not have existed without the context of the society in which it was created, that context including tax and the spending it funds.
I then went and looked at a wikipedia page of what UK government revenues are spent on, and I added up that two thirds of it went on essentially optional social spending. In my opinion it would make no difference to aggregate economic output whatsoever if this spending did not exist. It's purpose is purely to redistribute wealth and decrease inequality. Which are arguably good reasons for doing it, but it's a stone cold fact that the rich are made poorer by as a result of redistribution, just as the poor are made better off. (It's true that those of the rich who came from humble backgrounds might not have got there without it, but once they are there, their personal wealth will be maximised if they pull up the ladder behind them. I believe that if they hadn't had help, the ecomomic niche they filled, would have been filled by someone else, their wealth accrued to someone else who had a better start in life. They would have lost out, but the economy in aggregate would have been no worse of.)