Well, scheduling and static generation require a cron job that writes the static asset at the predefined time. It all gets complicated from here. You can write the static asset when it's first accessed for example and from there on serve the static file, but that requires a database/storage as well, so you're basically back to square one.
I'd not restrict myself to sqlite here either, but that's a minor nitpick.
Why does it require a database? Ghost has a Markdown editor and presumable stores posts in the database as markdown, just write the markdown to the file system instead of a database? I'm really not seeing any requirement for a database here.
Well, yes, you can write to the filesystem, that's why I'm saying "database/storage". See, heroku for example does not provide you with a writable filesystem and it's also easier to share a database over a couple of hosts than a filesystem. Also, if you want to schedule, you'll need to store the scheduling information somewhere. You can add it to the file itself, just as jekyll does but then you'll have to open all docs just to see if they need scheduling. Or you write a schedule-file, but by the time you're doing that you're effectively building a database. Why not go and use a "real" database adapter and use sqlite for all basic setups since basically, sqlite is a specially formatted file with a library providing useful abstractions on top.
Well, scheduling and static generation require a cron job that writes the static asset at the predefined time. It all gets complicated from here. You can write the static asset when it's first accessed for example and from there on serve the static file, but that requires a database/storage as well, so you're basically back to square one.
I'd not restrict myself to sqlite here either, but that's a minor nitpick.