> My impression of the licensing change was not that they expected to Amazon to pay fees for offering a hosted MongoDB service. It was instead to lock Amazon out, and keep MongoDB Inc. as the only "cloud provider" of a hosted MongoDB service.

Oh absolutely. I don't think they really thought they could force Amazon to license MongoDB, but I do think they believed they could force Amazon to not offer something that competed directly with Atlas.

That hasn't worked out for them very well.

(Not that I think leaving the license alone would have worked out any better. To the best of my knowledge, the MySQL, Postgres, Redis, and Memcache projects have not particularly benefited from Amazon building RDS and Elasticache on top of them, and I see no reason to think Amazon would have contributed a bunch of great patches upstream for MongoDB either.)