I guess this has more to do with teaching than the language itself. No natural language was "designed", they evolve, mix, and split. The rules were extracted from the language, not the other way around, that's why there are so many (and corner cases). They try to categorize words, explain syntax and define what is correct and what is not. Problem is: the language evolved past current rules and many do not make that much sense anymore. Should we go back to how English was or update the rules?

In that regard, we shouldn't even be writing like this. So many letters were taken out of the language and we now have many look-alike words that sound completely different. Tough, Though, Thought, Through, Thorough... If you learned French you are well aware of how utterly different is written French to spoken French.

So back to your kids, it makes little sense, indeed, to teach all these nasty rules and corner cases if that's not how they speak. On the contrary, maybe kids should be helping define what these rules should be