Nonsense. If the main cast is nothing but twenty-something's then for sure I won't bother watching. I like to see some seasoning in characters rather than a bunch of testosterone and angst driven kids. This would be little different than JJtrek. It also smacks of ageism.Sci-Fi audiences tend to be youth-oriented. If you look at STAR WARS, for example, those who are EVIL, for the most part, are old and those who should be calling the shots in the universe are in their teens, mostly. Like Padme and Luke Skywalker, verses the Emporer and Darth Vader. The bulk of the U.S. military is around 20. Having a very youthful cast in the next STAR TREK is going to be a crucial ingredient to locking in solid ratings. Old people out there in the audience were young once, too, and they'll relate to that aspect of it. And, naturally, the crew will have parents and elder statesmen and so forth to come on board, occassionally to drive stories and further adventures ...
When I was a kid I looked up to Batman and not Robin. I admired 007 who definitely wasn't a kid. And nether were any of the main characters of TOS and TNG. I'd rather see a seasoned Kirk, Spock, McCoy or Picard in action rather than some wet-behind-the-ears kids. They're doing that with JJtrek and it sucks large.