Donating large sums of money to charities removes a large amount of money from the income tax, seeing as charity is tax-deductible. Basically, allowing tax evaders to donate to charity is just helping them to pay less taxes, and therefore, make the council an local government systems weaker.
Also, charity is a great method of money laundering, as it allows people to quickly get rid of ill-gotten money and makes them look like saints. I personally don't think that the Mafia and tax evaders should be allowed to look like "good" people when they are really only helping themselves by donating to charities.
Donating to charity is a good thing which helps people. So if someone who is bad donates to charity at least they are doing something good. We don't encourage people to become better by stopping them from doing the good things, only be stopping them from doing the bad things,
The UCLA returned / rejected a $3M donation for kidney research from Donald Sterling because his "divisive and hurtful comments demonstrate that he does not share UCLA's core values." If I needed a kidney, I for one couldn't care less if Charles Manson was the donor. Keep the money, I say.
Are any of us good purely. None of us are without imperfections. Who are we to say who's the bad people donating. We all have been capable of pure evil. We shouldn't turn down anyone. The person you think is bad can be the one who actually is good-natured. Leave the judging of the heart to God.
Who cares? If I were sick, I'll take money from absolutely ANYBODY no matter how horrible I believed them to be. I'll take money from a serial killer or even a pedophile if it means staying alive. Who actually wants to die? Everybody has done something wrong real or perceived. Everybody's told or at least laughed at a racist, Sexist, Homophobic, Transphobic joke before. Everybody's lied. Everybody's stolen something at least once. If doing something wrong means that you're not good enough to donate to charity, Then that's so many people that would end up dead.
And given that nobody's a saint, We're not in heaven. Then if a bad person wants to do SOMETHING good with their life, Then we should let them. We would create more good people if we don't punish people for the good that they're trying to do.
I'm not really saying that charities are beggars, but if the money is gonna be put to whatever good use, I'd take the money from Hitler himself. At the end of the day, especially for charity organizations, money is money. The person behind the money doesn't matter. I'm sure a charity based around African Americans will accept money from a spitting, hateful racist just as quickly as they would from Martin Luther King himself