Because despite how great SQLite is (I use and love it myself), removing the "competition" between multiple implementations is removing one of the main cornerst

Because despite how great SQLite is (I use and love it myself), removing the "competition" between multiple implementations is removing one of the main cornerstones of the web platform. A real spec is "loose", it allows wiggle room in many areas, it allows for multiple ways to implement things, it allows implementations to act differently, and in most cases that comes out as a win for the user. Saying the spec should do what a single implementation does is about as close to saying "you aren't allowed to improve this" as you can get. I really believe that a monoculture is a bad thing. Luckily on most platforms SQLite (while the best in most cases) doesn't have a monopoly on what it does, and while it's a "defacto" standard in many cases, there are alternatives at every step of the way. Saying that a platform must implement SQLite takes that defacto standard and codifies it. It's forcing a monoculture. It doesn't just deincentivise improvement, it almost explicitly forbids it.