Yep, over and over again, "worse is better" proves itself as the all-important software mantra. Get that flimsy "database" out the door and loop back around to fix the "eats data" bugs 5+ years later.
The key to adoption seems to be to pinpoint something that people really want ("super fast 'SQL database' that I can run virtually for free" c. 1999), rush out a one-fifth-working version of the headliner features and pretend like it's all well and good, and then work to spread that solution as widely as possible.
Once you get the momentum, it's impossible to stop, and someone like Sun swings by to ask if you'd mind taking a billion dollars off their hands.
I don't think there's really a credible argument that technical merit has anything to do with success or adoption anymore (beyond just "superficially appears to work"). MySQL is a good specimen, but JavaScript is the real poster boy for the indisputable triumph of "worse is better".
Not sure it beats PHP in being worse. But at least both got substantially better with recent versions.
It provided fast relational SQL database for the early web application stack without any concern of maintaining ACID (Atomicity, Consistency, Isolation, Durability) that "real" databases like Postgres providied. It had slight speed advantage and that was enough to turn the scale against Postgres.
MySQL was demonstration of Worse Is Better in the database world. https://www.dreamsongs.com/WorseIsBetter.html