Jets GM Mike Maccagnan has shown that he's not afraid to take chances on the trade market, it worked before the 2016 season trading to Brandon Marshall and even Ryan Fitzpatrick but trading for Ryan Clady most definitely did not work.
After D'Brickashaw Ferguson retired, Maccagnan decided to take a chance and trade for Clady because despite his recent injury history he was an extremely talented left tackle and tackles that talented are rare. Clady got hurt again this year, and didn't play great when healthy, but it was still worth a shot.
Whether or not Clady can still play will be up to Clady and the rest of the NFL, but with a $10 million cap hit coming up this is hardly a surprise. According to ESPN's Adam Schefter the Jets informed Clady's agent that they will be decling the option which of course allows them to spend that $10 million on other players, players that they hope will be able to stay healthy and contribute.