The few successful startups I've known actually didn't have many "lows", and certainly not "dreadful" ones. They had a lot of stress, insane work hours, no life/work balance at all (since "life" was removed from the equation), but not too many of the kind of "omg we're actually failing" type of lows.

The cruel truth is that this business is so competitive, that if you make too many mistakes you're going to lose to those 1 or 2 among your hundreds of competitors that were lucky and competent enough never to have these kinds of failures.

In any case, I agree about the failure to distinguish fundamental (and very different) motivations here. Certainly you don't want someone crumbling under stress, but these kinds of people are easy to identify. Did that person had a very long vacation after leaving (for whatever reason) a startup? Does he seem to shy away from risk, stress, and high pressure positions?

If so, and you're hiring for such a position, it probably shows obliviousness and lack of self recognition and maturity for him to even apply.