I'm going to give Marissa Mayer the benefit of the doubt and just chalk this up to one of those things that people say simply without thinking. Sort of like Dan Quayle quotes from twenty years ago:
"It isn't pollution that's harming the environment. It's the impurities in our air and water that are doing it."
"Republicans understand the importance of bondage between a mother and child."
On the other hand, I'd like to expand her logic and suggest that good CEO's are a dime a dozen since everybody has financial and management responsibility for their own household!