This is how Dodge explained it: "The engineering background brings a rigorous thought process that questions assumptions and requires accurate data in the decision process. That doesn't mean every decision will be perfect, but it will be based on data...not opinions."

I think that strategy is unimpeachable. I've worked at plenty of non-engineering companies, and the inability to question assumptions seems rampant. If Google manages to avoid that, then whatever it costs will likely be worth it.