I think at the time Honda, Toyota and Nissan each introduced their premium brands, their overall reputation for building quality cars was quite a bit higher than Hyundai's at the moment... For the most part, Hyundai is still being laughed at for being an inexpensive, value-first brand, especially in the states. Granted, mostly by ignorant people, but nonetheless, public perception is what it is. If they came out with a premium brand right now, I don't think it'd be regarded that well. By starting slowly and introducing premium cars under the Hyundai nameplate, they're playing it safe and limiting the risks. When the public starts realizing how great these premium Hyundai vehicles are, then it'll be time to introduce a proper premium brand.