UE and Source both have much more reasonable license terms and smaller-scoped games will go with Unity unless they build their own engine.
My guess on what they are probably looking for is probably desperate indie or small-size studios that want something bigger than unity, they'll give a bunch of AWS credit to them in order to try lock them in. Even that is a long shot.
Edit: Had another read through this. Honestly I still don't see what the attraction is. There's bigger names out there with better engines and more favorable agreements.
Edit 2: Mixed up engines.
Forced/licensed integration may not be for some people, but this isn't that expensive, comparatively, in the end.
My point was basically that Amazon's pricing isn't outrageous, comparatively.
Of course Amazon wants lock-in. It's what they're selling. But we all make decisions about who we want to be married to and to what degree we want an open marriage. All of us in the game (et al) industry are "locked in" in many ways.
> Q. Is Lumberyard “open source”?
> No. We make the source code available to enable you to fully customize your game, but your rights are limited by the Lumberyard Service Terms. For example, you may not publicly release the Lumberyard engine source code, or use it to release your own game engine.
What's really interesting is that you can't use Lumberyard to communicate with game servers if they are hosted on a competing cloud platform; only AWS or server hardware you own:
> Q. Can my game use an alternate web service instead of AWS?
> No. If your game servers use a non-AWS alternate web service, we obviously don’t make any money, and it’s more difficult for us to support future development of Lumberyard. By “alternate web service” we mean any non-AWS web service that is similar to or can act as a replacement for Amazon EC2, Amazon Lambda, Amazon DynamoDB, Amazon RDS, Amazon S3, Amazon EBS, Amazon EC2 Container Service, or Amazon GameLift. You can use hardware you own and operate for your game servers.