The Wordpress of Databases
MongoDB is the wordpress of databases. ie: People really wanted a database for their product but didn't actually know what they were doing, so they used something that was easy to hit the ground running with.
This is now the end result, for the exact same reasons that Wordpress is a security cesspool, and it will never change for pretty much the same reasons. It's not a failing of the technology per se, but the fact that it enabled morons who would ordinarily find burger flipping challenging, to push out software products.