Oh, not at all — but it does make the potential hubris of a rewrite (slightly) more understandable. When you have no time for a rewrite because competition is fierce, the question never really comes up; it's not necessarily the conscious avoidance of "second system effect" that it might seem.

Well, I think the GP is just saying that it's all the more tempting in that circumstance. If it looks like nobody's breathing down your neck, you might be more willing to risk a rewrite. And we love writing code so much that I think we've all heard the siren song of starting afresh.