- Inexplicable perversity of human nature. - The clever machinations of MongoDB's marketing people. - The AGPL license killed it. - We spent too long development before monetizing. - Bad performance. - Numeric types limited to a 64-bit `float`. - Great product, but didn't/couldn't translate to revenue. - Bad business model. - Failure in timezones/timestamp nuances. - Document databases are a bad idea. - Investment dried up due to noisy market. - Did not solve problem companies using databases and having money need solved. - NoSQL hype died out. - No Java driver / automatic failover for too long. - No cloud service. - Trying to ship a cloud service. - Failure of capitalism. - MongoDB has done a way better job at SEO. - Realtime technology was too early. - Didn't build good sales/marketing teams. - Bad name. - The product was too good. - Didn't have a Heroku addon.
I'm no marketing guru and I have a lot to learn about economy myself,
and wanted to offer an idea that the very same
The same with "developer tools" market: corporate software development
May be I'm mistaken, but my 2017_04 understanding is that the main beneficiaries
Sometimes there are also some hybrids, like the Linux Torvalds's Linux and Tucker Taft's ParaSail and the Yukihiro Matsumoto's Ruby are, which start as a lonely wolf's hobby-project and then it gets picked up buy some group of people, who need it for either a hobby or for educational purposes or for work and then at some point some company basically gives the core developers and founders a salary based development grant. The LLVM is a kind of a hybrid project in a sense that in stead of being founded by a lonely wolf the compiler project was picked up by BigMoney (Apple) after the project lived as a grant based academic project.
As of 2017_04 I am really not aware of any technically successful, open source, long-term projects, where the more sophisticated version of Banksters, generally called as "venture capitalists", had given a project a life. In that sense, it's a very nice thing that the founding company behind the RethinkDB failed, because now the financing model of the RethinkDB development can be honestly fixed. I suspect that the most likely scenario is some scheme, where someone, who already has real costs (read: the party spends money) sees the RethinkDB as a way to reduce costs, just like Linux saved Google from buying Microsoft Windows Licenses for all of its thousands of servers at its datacenters.
I like the idea that
Anyway, thank You for reading.
Just read Slava's explanation  and the 2nd to last reason on this list makes the most sense.
"The product was too good."
Bingo. Engineering pitfall.
I was part of VC startup, not as a founder but 2 years in, engineering built 1 product, legal & biz folks did it on the opensource core model (80% OSS/20% closed), and -- big point -- we had a powerhouse of sales, marketing, and partnerships. That big point worked for our little startup if you count getting acquired a success (because a 35% return to our VCs should be considered as a success). Whether acquired/sold or going big, it seems Slava's essay echoes back to the lack of a sales, marketing, and partnership group early on at RethinkDB. He admits to focusing on the engineering for 3 years! That's a lot of cash to burn with little/no revenue even for Dark Startups.
Engineers have this idea that if you build it they will come. Ok, but how do they know to come?! Especially if you're 30 guys coding away all hours of the night, with the occasional Meetup pizza, and the only folks seeing your hard work are fellow engineers following your git commits? Followers of Github repos tend to not pay for software. :) So the point is nobody with a checkbook will know.