Yes, as a Spaniard who has been exposed to AZERTY in the past, I simply cannot understand the logic behind giving é, è, à, ç, and ù such arbitrary individual key allocations, which then make them explicitly untypeable as uppercase letters using the Shift (= "Majuscule") key... which as a result is required to type digits (majuscule‽). However, somehow the diaeresis ¨ and circumflex ^ diacritics deserve their own deadkey to be able to type ê and ï. I see this "improved" AZERTY leaves most of these issues untouched.
Meanwhile, in a Spanish QWERTY, reinforced by its requirement to support Catalan and Galician, ç and ñ have their own keys which can be uppercased as normal, and the acute `, grave ´, circumflex ^, and diaeresis ¨ all have their own deadkeys which can be used with any vowel character, uppercase or not.
Oops, answered to the wrong comment, reposting it here:
One reason to prefer specific keys is accessibility for those with fine-motor issues is one. I Detailed a bit in https://news.ycombinator.com/item?id=29229583. It is probably not the reason why it was designed this way but it's a nice corollary effect.
Another is that those characters are used often. Way more than some other letters such as x, y, z, k and w, and using a compose key so often would be a pain.
