I've said this before. Rex, against what many of us think, is not looking at this team in the ultimate rose colored glasses; he knows this team needs work and its not like this perception will automatically change if the Jets miraculously sneak into the playoffs again. A playoff run, no matter how deep, will not erase the shaky play the Jets offense, and sometimes defense, has shown us this year.
Making the playoffs will also make this off-season a more successful one, its easier to sell a playoff team to a FA than a team that missed out. It doesn't matter how close you came its much easier to sell a player on playing in late January than sitting at home watching it on TV. Nothing sucks more than narrowing it down to two teams and watching the team you could have signed with play while sit at home. Some people might want the higher draft pick, but it doesn't matter it has been proven that all-pros, and complete failures can be found at any part of the draft.
Team pride. Confidence is one of the most important things an athlete can have without it has next to no chance to succeed. Teams streak based on their confidence level. Making the playoffs will give the Jets a confidence needed going into the next season while missing something will add a sense of urgency that could stress out the team. Sometimes I wonder if Rex's guaranteed Super Bowl does more harm than good. Also making the playoffs makes the fans happy and if we're not happy its not an ideal situation for the team.
In the end the people who say it would be better for the Jets to miss the playoffs are thinking correctly, but don't realize that everything the Jet's get by missing the playoffs they also get by making the playoffs and more.