In some ways that's just an English thing, I think. I mean English has gobbled up a little of every language on earth like some language Blob and it's all mixed together. Imposing a structure on that mess is tough. Like those 19th century grammarians that tried to impose Latin structure and spelling on English and... well, just gave us even more of a mess and added to the confusion.
But also Japanese is spoken almost exclusively by Japanese people. That makes it much easier to control meaning. I imagine in the future as more and more immigrants come to Japan, this will change a bit.
Great points! I like the idea of having something so structured though. I'm kind of a nerd like that!