Mosquitoes and charity

Mosquitoes outnumber every other species on earth except termites and ants. (NZ Listener May 17, 2014, p.11) They cause 725,000 deaths annually. Bill Gates decided to do something about it and is funding research to instil Wolbachia bacteria in mosquitoes and block the transmission of dengue fever. This is ever so kind of Bill. He can afford it, he still has enough to live on. Other billionaires, millionaires, support other charities, opera houses, art galleries, churches and synagogues, hospitals, programmes to alleviate poverty. But should all these programmes depend on the private charity of the extremely rich? Are these not issues for the whole of society? If I were rich how would I decide what good cause to support? Should a cause get priority just because I happen to think that it is close to my heart?  Charity is something that is incumbent on every individual; not for some feel good factor, but because everyone should care for the welfare of others. But with the proliferation of extreme wealth there is a danger that charities that should be addressed by society will have to depend on the good will of wealthy donors, and should these donors not be in tune with a particular charitable cause such a cause would be ignored and neglected. When Prince Eszterhazy hired Haydn as the servant responsible for providing music in his palatial home he didn't do this as an act of charity. He didn't build opera houses or concert halls where people could enjoy Haydn's music. The fact that we can still enjoy Haydn's music, and get the benefit of Prince Eszterhazy's support for Haydn is incidental. Did Prince Eszterhazy use his extreme wealth to benefir anyone else but himself?