It is definitely worth remembering that the Jets moved after a few terrible years of bad drafting and horrible roster decisions left the team with basically no young talent. Chevy has done a very good job with drafting and a decent job of player development. He's had a few really good trades but he still doesn't address roster issues quickly enough (although that's true of almost all GMs, and the lack of trading partners hurts everyone).
I'd say he's too loyal, especially to bottom of the depth chart guys he overpays like Stuart and Thorburn etc. Sure overpaying a vet that everyone likes by a million dollars isn't the end of the world when you're not a cap team, but then sticking with them no matter what does hurt the team a fair bit. His inability or unwillingness to improve the bottom pairing is a long standing joke and arguably hurts the team as much as shaky goaltending (which he also ignored for years during the rebuild only to discover it isn't as easy to fix as he may have hoped).
Honestly, I'd be totally fine with Chevy being replaced this summer too. But the coaching staff definitely needs to go.