This purist mindset is killing the long term viability of open source. If hyperscalers can make money from successful projects but open source founders can't, in 10 years we'll have fewer open source projects.
Licence freedoms don't have to be all or nothing, or apply to everyone in the world. It can be open source and have restrictions. Anything else turns open source into a religion.
Not a religion, but a term with a specific meaning, which meaning implies a collection of freedoms granted without discrimination. People are welcome to use licenses that revoke those freedoms, but calling them FOSS is confusing and muddies the waters.
See Llama's license: if it can be Open Source while having restrictions, then having an Acceptable Use Policy is okay, right? So Redis could create a license that bans its use if you host adult content, Star Wars fan fiction, or documents containing the letter R?
If Open Source doesn't mean a license that indiscriminately grants a set of specific freedoms then it's pretty useless as a term—all I know on hearing it is that a project's source code is available. Which reminds me, we already have a term for that: Source Available.
Sort-of, we've had a litany of Postgres devshops go bust over the past decade. Some will be for the usual reasons but I wouldn't want to discount the impact of RDS.
However I think Postgres is a bit different. It's a bigger market and more widely used. There's a need for tuning services no matter which platform provides the database servers, so there's a level to make money above cloud hosting.
Licence freedoms don't have to be all or nothing, or apply to everyone in the world. It can be open source and have restrictions. Anything else turns open source into a religion.