While I know (and can appericiate) that the look of their character is an important part of the game for many people - myself actually included to some degree - I dont feel like the amount of work it takes them to develop and introduce new races has a huge enough benefit to the overall game and to most of the playerbase to warrant it.
I'd rather see them spend their ressources on either more "gameplay-content" (dungeons, trials etc. - stuff that you can actually play) or to enhance the "glamour"-options we already have (give existing races more options to pick from, like faces etc. or create more costumes and the like).

I might be wrong but I'm under the impression that often new races arent requested because they would fill a real void, but rather because people just want any new race - just for the sake of it being new. I can understand the desire for Viera, specially since it was an already known race AND they showed some concept-art and I kinda get why Hrothgar are going to be a thing (they really do fill a niche in the game). But beyond that I feel that we're at a point where we have a good choice between races and that a lot of follow up requests would be more of the sort "I just want something new!!" - which I just dont get... are people so unhappy with their characters...?
I just feel like even if our character-creator is limited, everyone should already be able to create a good looking character - so the amount of work stands in no relation to the benefit to me.

Even though I'm extremly happy that they added FemRoes as option with 2.0, I would have still enjoyed the game playing as a different character. Thats why the game to me seems perfectly playable and enjoyable, even with the races that already exist. Adding more adds to little to the overall experience of the game - specially for the majority of the playerbase who wont even pick one of the new races (whatever they might be).