I think the point is that for Amazon it's their own code and they pay full time staff to be familiar with the codebase, make improvements, and fix bugs. OpenStack is a product. The people deploying it are expected to be knowledgeable about it as users / "system integrators" but not developers. So when the abstraction leaks, and for OpenStack the pipe has all but burst, it becomes a mess. It's not expected that they'll be digging around in the internals and have 5 other projects to work on.