Even if the programmer's intentions are purely about code, and even if we assume management right now is entirely benevolent, data like that is hard to take back. If it is handed over to a Google that wanst to provide "photos that are actually relevant to you" right now, it will still be there if Google morphs into one that "sell your information to credit reporting agencies"

Overall I am a fan of Google's products and current policies, and I think some of the criticisms are overhyped. But with that said, I do think a "Google is benevolent, take our word for it..." statement should be taken with a grain of salt and an eye on possible futures.