So, he's hung around, gotten a lot of carries (#24 all-time), and now has compiled some stats which look OK for a career. He had two good seasons in New York, but I think those are overstating his NFL value, because he was playing behind a dominating line. Both years he had significantly lower YPC than his backups and even the team's fullback.
The last part applies to LT as much it applies to TJ. Tomlinson has had years where his ypc was lower (sometimes significantly lower) than Darren Sproules, Mike Tolbert, Jacob Hester, Michael Turner, Jesse Chatman, and Terrell Fletcher.I think what you're citing as a negative for Jones is a fairly common phenomena (where other part time backs gain more on a per carry basis than the lead dog).
Sproles had was a whopping 0.4 YPC better than LT despite LT getting almost all of the goal line carries. As far as Hester, Tolbert, Chatman and Sproles, you can't compare the YPC of guys who at most carried the ball 21, 25, 63 and 61 times respectively to someone who ran the ball 350 times a season. Turner is a great RB in his own right, but his YPC took a big hit when he started carrying the ball 20+ times a game.