Quoting Condi Rice.
When asked about liberating the Iraqi people instead of so many others who needed liberating, said that even if you can't liberate them all you can liberate some. (Still peddling the idea that Iraq was about "liberation" of an oppressed people.)
I think it's the principle. Even if the wealth of the Vatican wouldn't buy all Roman Catholics out of poverty, those spiritual leaders should live modestly, sparsely so as to be in touch with the congregants.
That opulence is absolutely obscene, even if you consider it's a sovereign nation.