We'll let them voluntarily pay more taxes then, or donate to charity, or start a charity or whatever.
By their very nature taxes are not voluntary, they're taken by force of law. Don't pay them then go to jail.
This is a stupid (but very easy) argument to make, one (of the richest)rich person says he'd be happy to pay more tax, therefor all rich people should pay more.
If he really wants to make a difference he'd be way better off spending his money on charirty, then it's not going to be entirely eaten up paying for beurocracy. THe government is not efficient AT ANYTHING.
When you pay taxes you're funding all that crap you don't agree with. Wars, funding for lobbies, paying politicians fat saleries, all those police raids on pot smokers etc. Why the hell would you want to give more to that?