As someone on the other side of the table at a startup, I always ask, and it depends on the answer.

-- Con: flight risk, collaboration risk

-- Pro: for valid reasons, they don't want the founder stress, risk, focus, whatever (say due to family, time, whatever), but love the environment. Such people are amazing: a classic "barrel" (http://firstround.com/review/Keith-Rabois-on-the-role-of-a-C...) .

We've been working the past few months with someone like this, and he is basically a multiplier on our ability to execute!