I started writing this comment by saying:
Exactly - the whole point of a cloud provider is scalability. If you're doing a personal hobby project, get off big scalable clouds and get yourself one (or multiple!) fixed-price VPS or dedicated servers.
But as I think of it, I think what people really want, for hobby projects, is not so much the scalability, but the managed offerings. They want zero-ops, zero-maintenance, zero-server-updates hosting, with a fixed price and hard limits. It won't be infinitely scalable, but it doesn't need to be - it's a hobby project.
They just don't wanna sysadmin a server of their own. Which is completely understandable.
There's room in the market for something like this.