It’s not a proper noun any more than granola is. Even if that point stood, when you get down to it, there simply are no “rules of language,” there is just making noises that other people understand or making ones that they don’t. You think proper nouns can’t have multiple pronunciations, well what do you call those little yellow, orange, and brown peanut butter candies? How do you say the capital of South Dakota? Speaking of SD, did you know there’s a town there called Sinai, pronounced “sigh-knee-eye” by its residents? I legitimately know a guy named Jurgen, one of his parents pronounces it with the J sound and the other pronounces it with the Y sound! It may be infuriating at times but that’s just how spoken language works. I urge you to embrace it as fighting it is fruitless. It’s also easier to get used to cringey new slang when you realize it’s a universal constant.
It’s not a proper noun any more than granola is. Even if that point stood, when you get down to it, there simply are no “rules of language,” there is just making noises that other people understand or making ones that they don’t. You think proper nouns can’t have multiple pronunciations, well what do you call those little yellow, orange, and brown peanut butter candies? How do you say the capital of South Dakota? Speaking of SD, did you know there’s a town there called Sinai, pronounced “sigh-knee-eye” by its residents? I legitimately know a guy named Jurgen, one of his parents pronounces it with the J sound and the other pronounces it with the Y sound! It may be infuriating at times but that’s just how spoken language works. I urge you to embrace it as fighting it is fruitless. It’s also easier to get used to cringey new slang when you realize it’s a universal constant.