Russell Wilson does NOT need to throw for a lot of yards to win. He can do it, but why risk the turnovers against great defenses when you win without it?
Plus, it sets up opposing teams who think all they have to focus on is the running game, because when he needs to, Russell Wilson can light it up. It's just there isn't a lot of separation between receivers and DBs. But Russell can squeeze it in there, he just chooses not to.
Remember the swing pass out to the right to Percy that he pulled back and ran with? There was a defender there that could possibly have picked that for 6. It would have been tough to do, but RW was not going to risk giving the game away.
Look at Wilson's passing stats from this year and how poor they look, I would argue that they look that way because that's how Pete Carroll wants these games played. If it's not wide open, punt the ball and live for another possession.
If it weren't for all the passes thrown away, Russell's completion percentage would be higher. If it weren't for all the times he has pulled the pass down rather than risk throwing it in to tight coverage, his yardage would be higher.
Here's an interesting stat for you:
"In the playoff games where Tom Brady has thrown ZERO TDs, he is 4 and 0. In 2013 game Tom Brady was 13 of 25 for 198 yards. In 2011 he was 22 of 36 for 239 yards 0 TDs and 2 INTs and still beat Baltimore 32-20."