Don't get me wrong, I feel with the Elastic team and I can understand why they're unhappy (even if I don't agree with their pettiness). I also don't particularly like the move Amazon did here. But that's why we want free software: If the current owner of the software does something you don't like, you can still use the software. That's the whole point.
And you're still free to pay Elastic to manage a cluster on AWS for you; Amazon might have forked the project, but it's still the customer that needs to switch to OpenSearch.
Not technically open-source, but much closer to open-source than what we would generally think of as "proprietary" software
Imagine just as an example, a license for personal software that is exactly the same as GPLv2 except billionaires can't use it. Functionally that has the same benefits as FOSS, even though it's not.
And it is in the best interests of FOSS to make it clear, time and time again, that the answer is no, and to work to ensure the answer is no.
Honestly it seems like the only downside there would be all the OSS purist/billionaire-defender HN commenters would have a field day, then you could move on.
I’d like to choose AWS to do this hosting in a lot of cases, assuming they’re willing. Barring them from hosting it is impinging on my freedom as a user and therefore with respect to whether I think that software is Free and Open.
That’s the exact freedom that Elastic is trying to remove here, for their own (totally valid) business reasons (they don’t want to compete head-to-head with AWS hosting), but in so doing, they’re removing an essential freedom from users. This is not about defending billionaires; it’s about having choice in the use of the software purporting to be free and open.
So it's a reduction in freedom, but it's not a reduction in user freedom.
“You have the freedom to contract for help with our software with this company but not that company” or “you have the freedom to contract for hosting in inefficient arrangements that we can beat in competition but not in efficient ways that we’d rather not compete against”.
The answer is simple - no. Either your product is fully free and you accept that people can fork it, even Amazon, or you choose a restrictive license. You can't make "free" (as in libre) compatible with "but".
I can totally see that you think this is unfair, but they did allow it and they were perfectly happy when being FOSS brought them market share. You have to take the good with the bad.