Because Star Trek's writing staff has always been overrun with somebodies...
Orci was probably the biggest name to ever pen a Trek film.
All Do respect to Simon Pegg ( I am especially a fan of Shawn of the Dead), he may be playing the role of Scotty, and he may have written for some of his own movies, but I am just not convinced he's right for this. I'd wager if most posters here were being honest, few actually knew who Doug Jung was before this article, without looking him up.
But let's take a look at some of the better Star Trek movies of the past:
Star Trek TMP (as was a number of ST books) was written by Alan Dean Foster, who as it happens wrote the novelizations of ST 2009 & STID, as well. I think HE would have been a good choice for Star Trek 13, actually. At least as one of the writers, anyway. He's a great sci fi writer and author in general, IMHO, and I think he could bring back more of that missing sci fi element.
Orci did have a lot of accomplishments especially with Herc and Xena, and you are better off NOT mentioning Transformers, but Harve Bennett and Nicholas Meyer had a hell of a lot more sci fi chops than Orci when each took on Star Trek. Bennett especially given his Six Million Dollar Man/Bionic Woman connection, which in 70s/early 80s were popular.
So I would say these guys were far from nobodies.
And I know all too well what forum I'm posting in with this thread (translation: I know there a lot of TNG-ENT era haters that post in here), but FC is one of the things that B&B and Moore actually got right, IMHO.
So bringing it around, I would have liked to see writer(s) with more sci fi experience.