The problem with the JJuniverse is that it's not new anymore. It's 7 years old by now. The JJverse won't attract many new fans anymore, and it isn't a "clean sheet" anymore either. But it has produced much too little content during it's existence.
If you have seen the JJmovies and became a Star Trek fan, chances are you have seen (at least SOME) prime Trek. Which means your major source for Trek knowledge is still the prime universe, even if you are a "new" fan.
On the other hand, if you are a fan of the JJmovies but have NEVER seen any of the prime Trek series, chances are you aren't that interested in a new Trek television series either.
Most of the "casual" fans don't even know, or care, about the timeline split. Just don't mention Vulcan, and the universes are almost identical. The only differences are cosmetical. And the new show needs to absolutely steal some of the JJverse aesthetics (and it does, as the trailer suggests), to reach out to casual viewers. But it still should be part of the larger Trek universe that has influenced popculture in the last 50 years, and is the reason why the JJmovies were successful in the first place. But who is more of a household name in genre fandom: William Shatner? Patrick Stewart? Or Chris Pine? The JJverse will get rebooted as soon as those movies have run their course, like Spider-Man get's rebooted every decade. And that's fine by me. Kirk and Spock are the only ones to have proven consistently successfull in movies ('First Contact' being the exception). But on television, Star Trek has proven itself to be more than just Kirk and Spock. It has proven itself to be a rich universe, allowing for almost unlimited characters, styles and stories. And that should be expanded on.