It seems reasonable to me at least to say: you can use this software for free, but you can't resell it. If you want professional support, please support someone who is maintaining the software.
Well, first of all I disagree that that's reasonable, but let's be clear here:
any license with a non-commerciality provision is not open source. This is explicitly part of the open source definition:
> 6. No Discrimination Against Fields of Endeavor
> The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
This is why Elasticsearch and Kibana are no longer open source; you have a choice of two proprietary licenses if you want to use their version.
It becomes just source-available software.
Being open-source to get a user base and then change the license isn't that great, they should have started as proprietary and that'd have been fine.
Now, I do think we are missing a standard license in this space - everyone seems to be writing their own, which limits those that can use them to larger projects.
You use Apache 2.0 when you explicitly don't want copyleft. But here's what's great: copyleft wouldn't even stop Amazon, so they have to use SSPL which is a proprietary license masquerading as copyleft.
Also, one way they were clearly outright reneging on their promise was that Elastic explicitly promised the community that the parts of the codebase that were Apache 2.0 licensed (the 'open core') would never be made proprietary. They broke that promise for this move.
And what's doubly hilarious is from a business perspective it's an awful move. It won't stop Amazon from making money - they'll just fork 7.1.0 and develop under Apache 2.0 like they just did, and keep operating their service just the same. And by the way, it's Amazon's right, legally AND ethically, to be able to operate AWS Elasticsearch for profit - just as Elastic is right both legally and ethically to use Lucene as a necessary part of Elasticsearch.