I think it's great that they are doing what they are doing to help others. What's the point of having a gazillion $$$ if you can't help others.
You have to stop and look at those who are very poor yet donate as much of themselves as they can, even doing without, to ensure that others have something.
If they want to help that is great, if they don't that is great too... It's their money, it was their talents/brains/know how that got them their money, they have that freedom to decide what to do with it.
If I was one of them, I certainly would be doing something for the betterment of society with my wealth as well. Mine would go into other areas. Soups kitchens, food banks, animal shelters, women's shelters, abuse centers, etc.