You may prefer Aeris, by all means. No one can deny that right for you. But ultimately, and I quote myself, for kicks

Originally Posted by
Fynn
Your sentimentalism is irrelevant in the grand scheme of things. Your existence is futile and finite.
The intent has always been Aerith, so all subsequent entries recitify that. Sure, a lot of people are nostalgically biased to Aeris and that's fine, but the story, as conceived by the people at SE, has always involved a girl name Aerith whose name got mistranslated, and they are now trying to make their vision clearer, since they have that opportunity. Aeris has been repelled from canon at this point, with Aerith being the one true Aerith, always (as Karifean and Sephiroth noted, it's even in the code of the game that uses Aeris).