There are a few problems with the Tanny drafts:
Lack of Depth: Trading so many picks to move up in the draft or for players from other teams has made the Jets a bit of a shallow talent pool. I don't know if there are any teams that have come close to the amount of draft pick trades that the Jets have done under Tanny.
Drafting Projects: many players have been guys who need some serious coaching. Talented and impressive at the combine but not so much in game situations. Example: I believe Sanchez can be a serviceable NFL QB that you can win with, but when you draft a guy with only 1 year of college experience as a starter you have to know he is going to need to be coached much more than a traditional top 10 draft pick. Like many of the players Tanny has drafted, they seem to lack Football IQ.
Over Confidence: Tanny seems to be too confident in his coaching staffs ability to turn athletic players into top level NFL producers. Example: Hill. A promising raw talented WR is elevated to #2 in his rookie season. Did he learn the nuances of proper route running in a few months?
I don't think anything I wrote here is a revelation to Jet fans.