Beyond that, there's not a lot of evidence for the notion that execs making more money is a net gain for the economy. It seems intuitive that more money in the hands of the wealthy would result in more investments and growth, but to the best of my knowledge there's not much evidence for that.
The real question is not whether handing the wealthy extra money is bad, but whether it's as good as doing something else. Sure, giving a wealthy man another million might get him investing more. Giving that million to the economy at large might do more, though. After all, those same investments you say the wealthy will make could be made by average joes.