This is the exact kind of comment I was warning against.
The "it surely can't be the technology!" comment when yes, Shirley, it really can be. Even the best database systems I know (orders of magnitude quantitatively better than RethinkDB) have areas of technical weakness. And not just some areas, but usual gaping valleys. Nothing does everything well, and if it tries to it usually does everything below average.
Time to man up. Performance really was crappy? That only having a float for your ONLY number type really was kind of dumb? Having no native datetime was bad? Saddling timezones on the pseudo datetime was a brainfart? Milliseconds only was shortsighted? Horizon was a bad idea too soon? Document databases are the new object databases - forever 5 years away? Aggregates were poorly done? Nobody really knew how to do stationary time series properly (I read through the GitHub issues regarding this and it was laughable that these people called themselves database experts)? and on and on.
I'm not saying all of this is true. I'm saying let's be straight and not always blame sales and marketing or dumb consumers or C-level execs or everybody but our own crappy code.
Having worked for a successful(ish) database vendor, I can say that user stupidity (ignorance) is a major factor in database software success.
Literally no users, and almost no employees at the vendors, I would bet (if my experience is not unique) have any idea of the qualities of the software they use/peddle, its semantics or guarantees, or its performance characteristics or how to use it correctly.
This makes the technology secondary; what is most important is how well you carve out mindshare. Whether that is even primarily down to "good" marketing is something I doubt. In the modern saturated database market, it is entirely unclear to me how you win sufficient mindshare and trust to obtain a wide enough (paying) userbase.
I have no idea if RethinkDB was "good" or not, as I did not take the time to investigate; I have little interest in "document stores". It actually seemed to me they had some pretty solid engineering foundations; the kind of thing that the industry should value highly, but due to poor information is unable to price into their purchasing decision, and as a result is missing in many modern (especially OSS) database offerings today.
> I dislike cassandra immensely, but I still use it every day.
I feel your pain. There is very few robust database system that handle recovery well enough at scale, and for those without the deep pocket to keep a dba on hand there are very little choices.
For small/middle scale robust system Cockroach db is promising but still needs a couple years development, if it can survive without a monetization strategy long enough.
