Here's another take to support Spiller's statement.
As far as being close to a contender, how many teams in the NFL are close to contenders? This is a league with a lot of parody as far as teams that have a shot to compete in the playoffs. Three of the last 7 Superbowl winners have been wildcards (2010 Packers, 2007 Giants, 2005 Steelers). With a team's win total coming down to a handful of key plays each year (dropped TD pass, muffed punt, missed FG, etc), the difference between an 11-5 team and an 8-8 team is as much about consistency and luck as it is about talent.
The Bills of last year were 6-10. Add some consistency (what Spiller said was needed) and luck to make the key plays that turn the tides, plus more talent and depth to escalate their every-down play, and they can contend for a wildcard spot.