"Pretty" characters is just a staple of the series at this point. I wouldn't go into your average western RPG with a more gruff, realistic style and demand that everyone turns into a bishonen, because that's not what the series is aiming for.
In terms of diversity, however, I agree. The amount of notable black characters I can think of in the entire series can be counted on one hand, and only Terra and the girls from X-2 are repping the ladies in terms of lead roles (unless you stretch and include Ashe).
I also see the whole 'anime is white people' thing far too often and it makes me fairly uncomfortable - I'm fairly certain that the Japanese artstyle, created in Japan by Japanese people, is not solely creating white characters. While I definitely agree on needing more diverse cast members in the games, I think writing the current cast off as white is severely missing the point.