I was thinking more in terms of ameliorating the risk of building a successful small business on this and them going out of business after gorging themselves on VC money and having a heart attack.
You could probably rewrite your thing in Django or similar in the event of that. Given that the majority of web apps don't turn into successful small business it might be a good way to try stuff.
My use case is closer to being a small dev shop doing webapps for other people. If they go out of business, I would have tons of Django/whatever work all of a sudden, but lots of pissed off customers when I don't have time to rewrite them all. Plus I (morally) would need to warn them about this risk when pitching/selling them, which would probably put a sizeable dent in sales: "Also, there's a chance that this completely separate company stops supporting their product and we have to charge you for a complete rewrite of your app".
