I tend to treat Mongo similarly. At my job, we hate Mongo and I've stood up and cursed it more than once.
Plenty of personal projects end up running on Mongo, because it has a rich query layer for quick hacking. I also never expect these to exceed the amount of RAM on my machine either.
Hell, in clojure I usually develop against a hash-map of hash-maps stored in-memory until the project gets far enough to re-implement the data layer (which I've hopefully abstracted well enough to not be a big deal).
Think of Mongo less like a schemaless postgres, and more like a persistent redis. Ease-of-use is its true advantage, and I think anyone who exceeds its capacity should be happy to have the problem.