A few people have commented on the lack of Black people who volunteer at programs which benefit Black people.
But the simple reason is that most Blacks don't understand the value of leaving a good tip.
Do Blacks get poor service because they don't tip - or do they fail to tip because they receive poor service?
"They need to get a better job" is the common response by those who fail to tip.
But think about it: If one group of people paid you a little extra for doing what you already do, and another group didn't - who would you prefer to work for?
To whom would you respond when a request was made?
It's not really being racist, it's just a predictive judgement based on passed demographic trends.
But what does one get from being a good tipper?
If one goes to Vegas, most of the tipped employees will direct any promotional deals your way.
Free rooms, free food, free drinks, free golf and free tickets to shows (all worth more than the amount tipped) can be had by the good tippers.
It isn't the amount you spend, but the amount you tip.
(The only exception is the fool (a"Whale") who loses ridiculously large sums of money and their only compensation are perks that are worth less than they've lost. But who wants to be that guy?)
The ability to render a good tip ensures more value for less money.
Now think about who volunteers.
Most of the people are people of means.
These people feel little inclination of charging for their knowledge or skill when a deserving situation arises.
Since a lower-class person will usually meet higher-class people by doing volunteer work - their pool of connections expand beyond that of "Pookie an dem".
Since these people are inclined to help people at no cost, they are more likely to help a poor person who helps other people.
A few hours of free work by a poor person (worth what they'd make at their everyday job) could be worth a few hours of work by a highly skilled and highly paid person.
They (the poor person) would get more than they gave.
They too would receive more value for their (lack of) money.