I can understand why a parent would do this. Really. They love the name
Emily, just hate its popularity. However, by avoiding the popularity issue, they have a trendy, made up name on their hands. It's just plain ugly. Changing the spelling of any name, especially when it's going to be pronounced the same, seems just silly to me.
Aidan isn't a bad name. I don't hate it, but I'm not waving the flag for it either. However, Ayden makes be cringe. If a parent wants their kid's name to be "unique" and different, then don't name it something that popular. If one truly loves a name, accept that others do to. Don't try and change the spelling folks. There are variations and then just plain insanity.