Earlier quoted context omitted.
The reason it's good is because, although it is bad, you never have to worry about it in terms of maintenance, admin or scale. It's like lambda for databases. For the same price, you can run a much more capable PSQL instance with way better features, but now you're on the hook for it being up 24/7.
They should really call it "data-structures as a service" rather than a database, really. Programming against it always reminds me of Leetcode problems, having to define your columns in a way to suit the very specific lookup patterns that they allow for.
I mean this reminds me of Firebase v1 and FoundationDB I think both of which have a favorable reputation for quality in both design and implementation. I do think there's something to be said for being forced to code against what operations are actually fast in your DB. Once it works you can be reasonably confident it will also be fast rather than the typical RDBMS experience of getting an abundance of rope with which to hang yourself with. You often won't find out until it's already load bearing that your query doesn't scale.