Yes, 6'1" is a great height in real life, but 6'1" is not tall in this game.
We have to realize that real-life height doesn't equate to in-game height.
Male Midlanders can go up to 5'11", and while that's a good height in real life, it's short in this game. There are many other races that go well over 6'1", such as Roegadyn, male Au Ra, Hrothgar, and Elezen. Even the tallest Midlander would seem short by comparison. So while a 6'1" male Viera would sound dreamy in real life, he would be much shorter by this game's standards.
Look at this chart.
If max height male Viera turn out to be the same size as male Midlander or similar, they wouldn't count as a tall race. They would be another short male race.