If my app completely stops working during a beta, are you suggesting that I should just wait until the actual release to find out that my app is in fact really broken should that be the case? And only then develop a new release for my app and release it as soon as possible, all the while having a deficient product for however long this may take?

I've always viewed a beta as a way to test that my app has not regressed. If it has, I open issues with Apple (or whomever). If these issues are either cited as not-to-be-fixed or I hear nothing back, I will create a release of my apps that works around whatever issues are there. IMO determining breaking changes in beta versions allows one to develop fixes as well as create and plan the rollout of the new software before the beta goes lives (and therefore avoid any regression/downtime).