I can only imagine what the team at Realm is thinking after going through comments and the post-mortem. Realm was an open-source mobile first database for the past 3 years. It's free. Its the most correct, consistent, and simple mobile database that is running on millions of devices[1] (Yup fine, kind of my opinion but trust me mobile community will back this up). They ship FAST, they ship real USECASES. They just recently entered the cloud space with their Mobile Database Platform, and they are even experimenting with new things like a version built for Node.js.
I'm honestly not trying to make a specific point, but asking more questions... Is mobile different? Is it easier? Are mobile developers more willing to try new technology? Are they more willing to pay for technology? (Realm is free, haven't paid them a penny, so not sure about this one...)
My main point I guess is that it's not a terrible market, Realm made it work with VERY similar ideals and goals. So what else is going on here?
[1] https://realm.io/news/jp-simard-realm-core-database-engine/