The "issue" here is just how DoA is perceived in the FGC. It's seen as an over-sexualized game, but mostly because of DoA-X/DoA-X2. However, since for some reason this has become a problem in the third installment of DoA5 (laughable), the bikinis and other fan-service costumes are banned from tournament play. As if anyone used them regularly.
Free Step Dodge
Bushido
Pink Nitro
I honestly don't see the issue with those costumes, I mean, their opinion shouldn't matter. That's their problem if they can't look past the "omg bikinis EWWW" give the game a try.
Bushido
Most gamers are close-minded.