My guess is lack of time on both fronts. We already know that Hrothgar were under a time crunch even as far back as their reveal, only being media ready the day before the show at the Japanese Fanfest - and that the dev's previously thought they wouldn't be able to attach headgear to either race. It was explained to be a technical difficulty but honestly speaking I imagine it was likely a time based one given the fact that developers were able to crunch on their own time to get a good swath of headpieces to work out of the gate.

I think the real test for me will be whether or not the buyable hairstyles are available once the expac drops. Stuff like the Lightning hair didn't show up in the Benchmark regardless of race, so it's hard to say if Viera or Hrothgar are 100% limited or if they'll have at least some extra options come patch day. Either way while I love SE a lot for trying to give us two races, I very much think they bit off WAY too much.