I see your point but it's not that clear cut in my experience because even if two languages share the same alphabet the way it maps to pronunciation can vary wildly. If you take random made up words like "tothon", "ylho", "sturcti" or "boqurkït" and ask English, German, French and Portuguese people to pronounce them as words in their native language you'll get wildly different results. So in a way you have to learn to override your native language and re-learn to read when you're switching to a foreign tongue, even if it uses the same alphabet.

Latin alphabet might give you the illusion that you can read a text aloud but it's really just that, an illusion. Ask a French speaker with no knowledge of English to read this comment aloud "phonetically" and see if you can even recognize the words.

It's even conceivable that using a different alphabet actually helps you getting the pronunciation right since you might be less tempted to read it in English.