Read Bent's thoughts after the jump...
While we can nitpick some of the rankings here (Coples and Wilkerson in particular), I'd actually say that where they have placed the Jets in their rankings is pretty reasonable.
As you can see from the color coded chart, the Jets have a high number of players on their roster that are either rookies or players that have yet to prove themselves. This mostly impacts upon their depth, with Kenrick Ellis being the only non-starter who they would regard as an "above average starter". However, the majority of the second and third string would have to be classified as unproven rather than just not good enough.
In terms of their projected starters, thing look a little better (and certainly an improvement on last year) with nine players considered a "good starter" or better and many of the players regarded as below average either being young players who have the potential to get better this season, or established veterans who are capable of being better and whose struggles last year can be at least partially attributable to the players around them.
On the assumption that Stephen Hill will be relegated to a backup role unless he develops this year and that Tommy Bohanon is not likely to have a key role, even if he makes the team, this underlines how important it is to get better play from the left guard position with Brian Winters the only remaining "poor starter" on the first unit. Average or better performance from him could elevate the play of those around him, which is what we saw from Nick Mangold in particular over the last month.
Beyond that, the Jets are obviously relying on Geno Smith more than anyone, but there are several other players on the team who are capable of performing better than this projection (which is, of course, based of 2013 performance).
Bonus link: ESPN New York's Rich Cimini reacts to PFF's take here.