I think MongoDB and Elastic did not expect that AWS would simply repackage their product and start offering it as a service becoming a competitor. Technically the Apache License that Elasticsearch was using allowed that, but ethics should have prevented it.
AWS could have approached the vendors for an OEM agreement or some sort of partnership which could have resulted in a "win-win" rather than pissing them off, up to the point that they had to come up with the nasty form of block that SSPL is.
People are often complaining that SSPL is created to please investors and bla bla bla, but at the end, even if the software was open source, the company was never supposed to be a no-profit, so I don't understand where the scandal is, and why everyone blames Elastic or MongoDB and nobody blames AWS.