The major issue with taxes over letting people keep more of their money is that each person doesn't have control over what they want their hard earned money used for. Instead you have a very wasteful machine now throwing money all over the place and not improving the lives of its citizens or providing them great options. Sure there are some but they GREATLY pale in comparison to the amount of wasted money.
You ever notice how wasteful large corporations are with money? Well the government is a mega corporation and I have to say it's not being run very well at all.