So apparently, every organized group of people find it neccessary to start a food/toy drive for the holidays. I've been hassled, daily, by my employer, my client, and now people walking through the neighborhood. I can't go into a grocery store without being accosted by some idiot ringing a bell asking for money, and just this week, my city decided to start fining people for their trash can placement.
So, apparently, society doesn't run so smoothly when you starve it for revenue. Charity might be able to help those in need, but it's inefficient, annoying, and done more to boost the ego of the givers than help the recievers.
The US government is not starved for revenue. It collects and spends about 40% of GDP http://www.usgovernmentspending.com/us_20th_century_chart.html
If you would give up a significant fraction of your income just to see a marginal reduction in the work of charities because they annoy you, you are an unusual case. But even then, it would likely be cheaper for you to hire someone to accompany you and deal with soliciting charities rather than pay the extra tax.