I don't think that's the case. AWS regularly runs AGPL-licensed systems as service in direct competition with the developers. AGPL, for the most part, patches some holes in the GPL license.

I could be wrong, but there seems to be a good amount of content regarding projects releasing AGPL to prevent commercial competitors from using the source code against the creator.

Maybe Amazon is too big to fight?

Some reading in case it's of interest:

https://www.google.com/search?q=using+agpl+to+protect+agains...