Tell that to David Gerrold.

He was excited about STNG then abruptly left. What did he do? He kept his mouth shut for years. Someone who disliked a show wouldn't say anything, whereas someone who does would be excited...and not only that, but as pointed out Mack doesn't actually have to rely on DSC for anything, his career is fine.
Same goes with Les Moonves who loves the first 6 episodes. He would never have said that he'd have simply said nothing, lest the show was terrible when it aired and stockholders and media would think he's an idiot when that was demonstrated.
I'm hearing that CBS is super confident about the show myself.
RAMA