Whether you give or don't give - ask yourself how you can help create a society where this sort of charity is unnecessary. John is privileged with semi celebrity - think of all those in his position who are anonymous.
Consider making the same donation to Watsi[1].
Your gift will go where you know it will do something meaningful (not that Barlow's health isn't meaningful, but the impact for a child vs. an older adult is vastly higher).
It also doesn't help matters when it shuts down people's soup kitchens for bureaucratic "violations", threatening them with prosecution, and makes laws banning "public food sharing".
It's all pretty good in the slums of Delhi right now I guess.
I'd have more respect for the "We shouldn't collect taxes some of which help poor people" if people objecting just straight out said "I don't want to help poor people".
Part of living in a society is that it is a society, I grew up in the UK, my parents paid taxes, those taxes went towards an orderly society, good policing, reasonable education provision, health care provision and a social safety net for personal disasters (injured, ill, someone dying etc).
Relying solely on peoples charity would be terrible, people are fickle, look at the ALS challenge, it raised a lot of money (a good thing) but I bet they don't raise anywhere near as much the following year.
How do you plan any kind of useful service from year to year when you have no idea what your budget will be.
Also if you want good services and don't want to pay more tax lean on your politicians to support policies that tighten the tax code for medium/large orgaisations (basically if they can afford to hire a full time tax accountant they should be watched more closely).