Because for YEARS, both the games (like Pokemon Stadium and Pokemon Stadium 2) and the 4Kids anime (both trainers and the Pokemon cries themselves) pronounced it "Ratta-ta," which not only sounds 100% correct (Ratta-ta evolves into Ratta-cate), it also just makes the most sense. Even breaking it down phonetically, that is how you would say it, hence the double T's, which means you stretch the T's in the first syllable. "Ra*tt-a-ta." That's even how the Pokemon said its name in the early anime 4Kids did; in a loud shrieking "RATTTTA-TAH!" sound.
But I STILL hear some dumb, stupid people call it "Ra-tattah" which makes me legit CRINGE every time I hear it. How TF could you pronounce it so stupidly for 20+ years? The official Pokemon Company and such never even called it this until recently. There was this crappy third-party app called Pokemon 3D and that was the first ever time something "official" from Pokemon started calling the purple mouse "Ra-tatta." Then the Sun and Moon anime did it one time in the only ever instance Alolan Rattata was mentioned in the entire anime arc.
If it was called that though, it'd be spelled 'Ratatta' with a heavy emphasis on the T's in the second syllable. Ra-tatt-a. But that isn't how it's spelled. It also makes no sense that a Ra-tatta would evolve into Ratta-cate and have a completely different pronunciation. Toe-ga-pee doesn't evolve into Toe-ghetik; it evolves into Toe-ga-tick. Same phonetic sound. Why would Rattata be any different?
Even typing 'Ra-tatta' makes me cringe cause it's such a horrible, retarded pronunciation. It's not like a "Lopp-punnie/Low-puni" situation here. Or "My-low-ick/Mill-lot-ic" thing. Or "Ar-kay-us/Ar-see-us" thing. (The first versions of all of those being the correct way to say them, by the way.) This should be clear to anyone who isn't a retard and learned English as a first language. Maybe it's because I have a masters in the subject and it's my career, that this bothers me so much. Then again, I don't get so annoyed when people do this to other words.
I'm not trying to make this a Chris-Chan thing with Sonic's arm colors, but seriously; can y'all stop calling the purple Kanto mouse a f'cking "Ruh-tattah?" It makes you sound so damn moronic saying that. It's even worse when they can't even get it consistently right in the Alola anime arc, not that I've watched the anime since the mid 2000s.
https://www.youtube.com/watch?v=h_8Wg3vXHfg
So yeah, that's all. That's my rant on people calling a Pokemon wrong for 20+ years.
there doesn't seem to be anything here