I recognize there's hundreds of different factors that played a role in the story of RethinkDB and its relatively poor adoption. I'd like to touch on one specific point (probably far from the most important one) - the name.

I think you guys introduced friction very early on with some of the developers, because of your name. Given the context of our times where many of the devs joke around about "yet another 'revolutionary' database that claims to be different and then does the same thing, but dropping some crucial functionality" (for which I primarily blame MongoDB), "RethinkDB" can be considered a bit of a sardonic name. It can also read as "we need to reject the notions other databases are built on and rethink it all", which to more conservative devs can feel as an attack on decades of thought and design around their beloved MySQL and PostgreSQL.

Basically, I think this name might actively discourage developers from adopting your db or at least playing around with it.