From their site:
OpenAI is a non-profit artificial intelligence research company. Our goal is to advance digital intelligence in the way that is most likely to benefit humanity as a whole, unconstrained by a need to generate financial return.
The money quote is at the end, literally—$1B in committed funding from some of the usual suspects.
Like this?
The first one is a non-answer, the second one suggests that a proper response to Dr. Evil making a machine that transforms the planet into a grey goo is Anonymous creating another machine which... transforms the grey goo into a nicer color of goo, I guess?
If you don't believe that a foom is the most likely outcome(a common and not unreasonable position) then it's probably better to have lots of weakly-superhuman AI than a single weakly-superhuman AI.