Abortion aside. The Gates foundation does have a useful focus. They are trying to use mostly existing technologies to attack disease worldwide (for example vaccines that do not require refrigeration etc). Such approaches can serve to alleviate suffering worldwide (a goal all conservatives should be in favor of).
I also agree with Buffett's decision to force the funds to be sent the year given and not be carried inside an evergrowing foundation which will outlive you and can be used for crap (like Rockefeller etc) which have morphed way beyond what they were intended.
the Rockefeller's built great museums in new york city, great buildings with great public spaces.
Except in the case of malaria. The foundation is mega-spending on a vaccine or other cure while ignoring the extremely effective solution while hundreds of thousands die of malaria every year.