Why did George Washington refuse to pay taxes?

You have it backwards. Go to google.com and search "whiskey rebellion".

After the revolution, congress needed some cash so they enacted a tax exactly like the one that sparked the war. It was a tax on whiskey, only paid by some hillbillies in Pennsylvania. Of course they refused to pay. G. W. personally led the army there to collect the tax at gunpoint. The descendants of those people still remember the event as if it happened last week.