It's not a binary decision. Those with the means can still chose to donate some of their money to causes they like, and we as a society can (or should) still chose the way in which we want to allocate public funds towards more health spending or away from defense spending.

Choosing to donate to a cause that affects him personally is no different than when people create charities or foundations or donate money to fund research for diseases that affect their immediate family members - which happens quite often.