When a team has a lead, they don't need to push the ball downfield quickly. Just milk the clock and get enough for a 1st down to continue milking the clock until they get in FG range. So some of this can be attributed to the other team not needing alot of yards. Plus the Bills special teams gave up a lot of big returns which gave their opponents a shorter distance to score.
Home run hitters don't win in the playoffs. They need a young power back who can get the tough yards up the middle and score near the goal line. Spiller puts them in 2nd and long way too much for a team that doesn't have a QB who can bail them out.
YPC is irrelevant when he has one long run and then gets stuffed for most of the rest. He's not consistent, and puts them in 2nd and long way too much.
Picking a guard at 9th would be a waste. Plenty of good ones in the middle rounds or free agency. That 1st pick has to be used on a skill position or OLB.