> For example when was the last time you complained about weak type systems when working with JSON, XML, or SQL tables? Well, I don't know about the person you

> For example when was the last time you complained about weak type systems when working with JSON, XML, or SQL tables? Well, I don't know about the person you're replying to, but I certainly complain about these all the time. Interestingly and counter to your point, I think, XML grew a "type system" of sorts with XML Schema (which is widely used IME, esp. where interfacing with external services as in SOA), and SQL actually has a reasonably strong type system for most implementations albeit dynamically checked at query planning time. (SQLite seems to be the outlier here.) JSON is actually the outlier here, but even with JSON there's been attempts at a sort-of type system with JSON Schema. Why? Well, because beyond a certain size the "just chuck some data somewhere in there" ceases to be workable when you want stable and maintainable interfaces between software components. Ultimately type systems are invented and used for almost entirely pragmatic reasons.