Reason #1: The "G" name. It was only recently that Infiniti squashed the "G" line-up. It was a signature car in Infiniti's brand, and helped set the path for the Q50. Some may draw some quick flash comparisons between the Genesis G cars and the Infiniti G series. Not a big deal, but that issue still presents itself.
Reason #2: Actually this is a good reason. This decision does help the Genesis and Equus become more serious in their respective classes. Even though the Hyundai now is 1000x better than what it used to be, the one thing holding the Genesis and Equus back was the fact that they were near luxury cars in a family visioned brand. Now the Genesis and Equus can start a new journey in a new brand made specifically for that vision. A third reason that could be either good or bad is now the Azera has some breathing room. Frankly the Azera has become a distant memory and sort of a middle man that divided the Genesis and Equus from he rest of the brand. Now the Azera has the opportunity to hopefully reset, and hopefully Hyundai pays a little more attention into redesigning a new competitive Azera.
Will Genesis be successful? Only time will tell. It is going to take a lot of years to fully grow the new brand to the size of its competitors. But Hyundai has learned a lot of good things over the years, and Genesis should do quite well in the long run.