Open source is fine, single corporate entities controlling and owning the copyright is not. That was always a problem and Elastic, Mongo, and Redis are forcing the issue by unilaterally changing the license and doing a bait and switch on their loyal users and contributors. They have the right to do that. That's the problem.

Linux, Mysql, Postgresql, etc. prosper and thrive with many companies collaborating and competing at the same time. These projects survive pretty dramatic changes to the companies backing them including bankruptcy, acquisition, hostile take overs, etc. There are many healthy open source projects like that.

What they have in common is that individual developers rather than a single corporate entity owns the copyright. This makes changing the license impractical. The best you can do is fork the code base and then hope developers continue to work with your code base. IMHO distributed copyright ownership is far more important than the license text because it makes changing that text impractical. So Linux is fine despite the legal pitfalls (perceived or real) associated with GPL2. It's a take it or leave it deal. Most of the industry seems to have taken that deal and is actively contributing and has found ways to bundle proprietary code regardless. So Linux is fine. It's used by mutually hostile companies and even countries. That's the whole point. The OSS community is a neutral place where you can choose to collaborate.

That makes the AWS fork of Elasticsearch interesting because they forked but don't insist on copyright transfers. They are going to do some legal checks to verify who you are and that you are legitimate. That's basically the nuclear option in OSS. It happened to Oracle when they took over Sun. Forking is a dangerous weapon and it tends to only be used when companies mess up the stewardship of their code bases.

That's basically what just happened to Elastic. This means that over time, the ownership of the forked code base will get more distributed and include lots of Elastic, AWS, and (mostly) third party developers.

Elastic employees will likely not contribute (or even be allowed to contribute) to the AWS fork. At least not while they remain employed at Elastic. However, Elastic might see some of their external contributors, former employees, and people from e.g. the Solr and Lucene communities contribute to the AWS fork instead of Elastic's "we own everything" non OSS copy. My guess is that this is exactly what AWS wants to happen. Drive a wedge between their contributors and Elastic. Never mind their motives, I actually think it is the right thing for the Elastic code base. And I say that as somebody who has been a long time fan, occasional contributor (and mildly disgruntled about Elastics recent moves) that has several friends, former colleagues, etc. working for them.

It's an interesting experiment that doesn't cost much to run for AWS. I don't think AWS is going to do much to make a lot of change happen but I'm sure they are happy to accept pull requests. If that start happening in more volume, the right move might be to eventually move control to the Apache Foundation. Amazon wins, users win, developers win, oss wins, Elastic & its share holders lose. Might be unfair but I prefer using open source and not betting my career on proprietary code bases. If successful, there are other companies that need to worry about losing control in a similar way.