Benjamin Olson
Hero
I think "no more subraces" is interpolating too much into the decision to present things in the most clearly comprehensible format (race/subrace-wise) for this UA. I personally like presenting things with subraces when multiple subraces are presented together with the race like in the PHB or the Volo's section on Aasimar, but it is irritating when you encounter subraces on their own to need to reference back to some other source for the race, and much more irritating if it involves bringing an extra book to the table to play your character.