I’m kind of curious why the decision to have implicit casting like this was made in the first place. I can’t think of a single upside other than not having to type out cast(foo as bar)
TCL was used as a dev wrapper language at the time, and it functioned the same way.
It was only in mid-2004 that SQLite 3 was released which used its own storage backend, and that allowed for the 5 supported storage types (int64, string, bytes, float, null). It was API compatible (with minor adjustments) with the earlier SQLite 2, so the lack of static typing continued, otherwise everyone would have to rewrite their code. You do get dynamic typing, which hasn't been a problem for the vast majority of SQLite users.
Do remember that SQLite is competition for fopen, not Oracle / Postgres etc. It is trying to make things as effective as possible in that scenario. If you don't want numbers in your string column, then don't do that!
I used to sort of dismiss berkeleydb(why so simple?), but a disk backed b-tree indexed key value store is not trivial to get right and having a prebuilt library to do it provides a huge value.
As of January 2006 you could add CHECK constraints using the TYPEOF function to reject that at the SQL level. And it is your own code - there is no server - doing the insertions. As was common back then, protecting you from your own bugs was not a high priority for APIs!