So what, just ignore all research and go with your gut feeling?

I would take one study with a grain of salt too. Even if the conclusions are correct in the setting of the study (and since most research findings are false, they probably aren't), it doesn't mean that you can extrapolate to every other setting, particularly the specific case of being the CEO of IBM. Hence "Make of that what you will."

But there could be an element of truth to it, which might warrant further research. If CEOs really do have a much more limited influence than they are given credit (or blame) for, then incentives perhaps ought to be adjusted, not just in the interest of fairness but also in the interest of finding better ways to actually improve performance.