I play Akiha because she's hot
Also because when I first got into the game, she was one of the few characters that actually appeared in a downloadable match video(the old bell vs linalys one on combovideos), and the thought of playing a fiery girl in a seifuku was too good to resist.
Besides V. Akiha being better, I guess Japan doesn't play her because of how popular she was before? Like in early ver. A/FT days, where Akiha was considered S Tier, maybe people got used to fighting against her or something, I dunno.