Mongo sucks. I've used it in production for millions of people. I would never recommend it ever again. It's convenient, about the same way a hooker is.
Maybe your app wasn't suited for what it's good as. A File system would suck as a relational database... that doesn't mean it sucks in general. I suspect you had the same problem with Mongo.
We continually hear about how great MongoDB supposedly is from its advocates, with them claiming it's suitable as a general-purpose database.
Yet when somebody who has apparently used it in a production setting speaks out against it and its numerous flaws, the problem isn't with MongoDB. No way! It's a "problem" with the app "not being suited for" what MongoDB is "good at".
I don't thing any database/technology is well suited for everything. And never said as such.
But as a counter point... We don't know this was a 'general purpose' problem... so your point isn't even valid even if you were responding to something I said... Unfortunate.