I don't get the point of this article. SQLite is fine, especially in an embedded database, but once you have concurrent access, it starts to suffer because it has very coarse grained locks, so a "real" database is better for a distributed single-DB design. It's more about using the right tool for the job, and the author seems to be talking himself out of some kind of guilt for SQLite being the right tool for him.
I think you're misreading the post. They're just trying to explain why sqlite is the right tool for their particular job, so they don't have to keep explaining it to other people who keep trying to shoehorn in the wrong tool. Lack of concurrency in their app is specifically mentioned as a reason sqlite is appropriate. There's no guilt there.
