They gave away three 2nd round draft picks to move up 3 spots in the draft to better position themselves for a quarterback in a quarterback heavy draft during a year where the FA quarterback situation was historically great.
In other words, they paid for a drink of a water while swimming in a clean lake.
Think of all the needs the Jets have on their team and the likelihood that whoever they get at #3 will be better than whoever would have fallen to them at 6, or whoever else they could have got in FA, or even Teddy Bridgewater (who they did get in FA).
New York Jets: How not to build a competitive roster.