X to Y Y to X A to B B to C
MongoDB to this MySQL to that Why we switched Why we switched back
blah blah
It's one of the oldest themes in computers - man, this software is crap - that new software will fix all our problems! Until you find the problems with the new.
Precisely the same age is the new software vendor harnessing all that negative energy about the competitor and megaphoning the "man, the new will fix the old, we're so excited!"
Having said that, I have worked with the compute servers of all the major cloud vendors and Amazon must be credited for the quality and consistency of its AWS systems, and Google and Microsoft's cloud computing is in almost all respects equally good - there is as far as I can tell absolutely no reason to choose Amazon over Microsoft Azure (yes, even for Linux systems) or Google Compute Engine. In some areas of functionality GCE and Azure I found to work much more easily and smoothly than Amazon. When I went to work with OpenStack I immediately found the lack of completeness, inconsistency and lack of polish characteristic of many open source projects - trying to do simple things instantly became hard problems.