I am of the opinion that the reason Tebow / Broncos were able to turn a lousy start into a winning season is because the NFL defense is all about stopping the pass. I believe the option game would force the defense to hesitate that additional second and allow the office to gain one or two more yards on average. It is all about exploiting your opponents weakness.
Tebow is a runner who can pass.
The option game works for a while. But it has certain innate limits. It cuts the field in half and removes a bunch of receivers from the mix. It develops plays slowly. And it volunteers your QB to get tackled a lot, which means he gets injured. And running a lot means a QB isn’t making passing decisions, which removes reps from him, which is why we see so many run first QBs not get better. Just look at he wild cat to see what would happen to the option offense, it worked for about half a season, then defenses got wise, and now it’s basically gone from the game.