I think the problem is not how understandable it is, but how robotic it is. This recitation of Miranda is so driven into our heads from TV and movies that I don

I think the problem is not how understandable it is, but how robotic it is. This recitation of Miranda is so driven into our heads from TV and movies that I don't think anyone would bother to parse it. If the language got "friendlier", I think the same thing would happen over the span of years-- again, if it was said exactly the same way, every time. Of course, if the cop mixes it up and uses different words and intonation, now they're opening themselves up to liability.