[IIAOPSW]

While completely true, I think this misses the point which makes minimal "natural" language interesting. Sure you don't use one of these constructed languages in practice the same way you don't build your websites with Turing machine tapes. The question of interest is not one of practice but of theory, what is the equivalent of Turing completeness for natural language? What is the minimum criteria of grammar and vocabulary needed to span the space of conversational ability? In other words, what is the minimum needed for a language to even theoretically be "naturalistic" (even if no naturally occurring language ever looks like it in practice)?