Comment by freedomben

This is the correct take IMHO. I generally dislike Amazon (and when it comes to things like the Kindle, I actively hate them for the harm they are doing), but I think this is the key. S3 is not and never has been advertised as an open standard. It's API was copied/implemented by a lot of other services, but keeping those working is not Amazon's responsibility. It's on the developer of a service using those competitors to ensure they are using a compatible client.

I do think some of the vendors did themselves an active disservice by encouraging use of the aws sdk in their documentation/examples, but again that's on the vendor, not on Amazon who is an unrelated third party in that arrangement.

I would guess that Amazon didn't have hostile intentions here, but truthfully their intentions are irrelevant as Amazon shouldn't be part of the equation. For example, if I use Backblaze, the business relationship here is between me and Backblaze. My choice to use the AWS SDK for that doesn't make Amazon part of it anymore than it would if I found some random chunk of code on github and used that instead.