Why Tabaxi claws use Strength, but the Shifter Razorclaw uses Dexterity?

@joshcoodyIs there a reason the Tabaxi claws use Strength, but the Shifter Razorclaw uses Dexterity? Or is that not the same thing? Not a useful comparison, since the tabaxi is an official part of the game and the shifter from UA isn't.

— Jeremy Crawford (@JeremyECrawford) December 15, 2016