"(Also, y cant zelda talk?)"
This is based on Link's outfit, not Zelda's, I don't really excactly know why he doesn't talk though, I guess it is fo the same reason as other VG characters; It could be a bit silly if the player's character talked in certain cases.
Anyways, dressing up Gardevoir s other VG characters indeed look pretty good for some weird reason, it's too bad about the body spike and the dress in some cases, as they easily get in the way.
@Miccs
In Borderlands: The Presequel the main character does talk unlike in the previous two installations, but it kinda feels unnatural though :\
It fixes a rigid personality to said character, leaving no room for the players themselves to explore their own identity of the character - Kinda like books vs movies.