"So, MongoDB got exactly what they asked for. It's just that, when they forced Amazon to make a choice, they didn't expect one of the options they gave them to be viable. They were wrong."
You're just talking narrowly about Amazon in this comment. What you said makes more sense if you broaden it to commercial users. They might have known FAANG companies, esp Amazon, would just ditch their software if they switched licenses. They might be targeting the companies that can't or won't build a MongoDB knockoff. The companies that will actually pay for their product. That's a huge market.
The product that Mongo offers is not the DB itself, though, but support and cloud hosting (Atlas). In practice, most people really only care about the latter. Now that Amazon is offering a competing service that is compatible, cheaper, and (if we believe their claims) better, the question for those commercial users is whether they'll pay Mongo, or pay Amazon. How do you think that's going to work out?
Depends on how Mongo is run. People going for low-cost, big-company longevity, or ecosystem tie-ins will go for Amazon. People avoiding big companies' complex offerings or bullshit might prefer Mongo. Note the existence of Amazon, Google, and DO havent eliminated the hosting market: more stuff available at lower costs than ever. Mongo might similarily have a shot it they differentiate themselves positively from Amazon.
You're just talking narrowly about Amazon in this comment. What you said makes more sense if you broaden it to commercial users. They might have known FAANG companies, esp Amazon, would just ditch their software if they switched licenses. They might be targeting the companies that can't or won't build a MongoDB knockoff. The companies that will actually pay for their product. That's a huge market.