Some possible argument against charities. Personally I think that it is normal to donate around 1 per cent of income in form of charity support.

1. Some can't survive on less or have other obligations that looks like charity (child support)
2. We would have less initiative to earn more
3. It would hurt our economy, as it is consumer driven. We must buy Iphones
4. I do many useful things which intended on helping other people, but I need pleasures to recreate my commitments, so I spend money on myself.
5. I pay taxes and it is like charity.
6. I know better how to spent money on my needs.
7. Human psychology is about summing different values in one brain, so I could spent only part of my energy on charity.
8. If I buy goods, my money goes to working people, so it is like charity for them. If I stop buying goods, they will be jobless and will need charity money for survive. So the more I give for charity, the more people need it.
9. If you overdonate, you could flip-flop and start to hate the thing. Especially if you find that your money was not spent effectively.
10. Donating 100 per cent will make you look crazy in views of some, and their will to donate diminish.
11. If you spent more on yourself, you could ask higher salary and as result earn more and donate more. Only a homeless and jobless person could donate 100 per cent.