Which is all the more poignant because at a higher level here we have Amazon confidently building on Google's platform, in direct competition with Google's own

Which is all the more poignant because at a higher level here we have Amazon confidently building on Google's platform, in direct competition with Google's own services, knowing they can do so without prejudice. Amongst all the argument about "open"-ness and what it means, whether it's source code or something else - for me this is the important part. If a competitor can build on a platform and safely do so in competition with the interests of the platform owner then that platform is "open" in the real sense that matters.