I think the main concern about more Beast-like races (not the example from the OP), is how to work them into the plot. Right now, a large part of the plot deals with the "human" races' interactions with the Beastmen. There is a clear divide between the two, both from a physical sense and from a spiritual sense (i.e. the Beastmen's connections to the primals).

While I would personally enjoy a playable beastman-like race, it'd be very hard to explain why this race of beastmen is treated completely differently than the others. For example, in Ul'Dah all beastmen are banned from City grounds. You'd have to be like "We ban all beastmen...except for that type, because they're cool I guess". The game's early plot deals almost exclusively with human and beastmen interactions, so I don't see how they can just add a playable one.

That's not to say I wouldn't like to see more variety between the races, but I think the plot thus far has kind of forced all races (at least for the time being), into being more "human" than inhuman.

That said, I'm all for cute harpy girls!