Well, for a native speaker this makes totally sense, as children speak the language for a long period before they even try reading. And creating a different approach for foreigners isn’t of much use probably as most will want to learn the spoken language, too anyways, and those who don’t need it can just ignore the furigana (or pay less attention).
I haven’t studied a tremendous amount of Japanese, to be honest, but I disabled the furigana pretty early on as they are wrong most of the time anyways, but I never had the impression that not knowing how to pronounce a word makes understanding the sentence harder or knowing the pronounciation makes it easier. It is motivating when I can remember both, though. 