Even though he's a chucker they always play him at point. You're forgetting that Greg Monroe is a restricted FA and he's going to command a big chunk of that remaining money if they match his offer. With a new GM and new coach they aren't trading anything for Lin. Maybe if Dumars was still around as he made a variety of awful moves but not now (unless you are suggesting them as a team that may take Lin if we give up an asset). This is all before you take into account how awful a Lin/Jennings backcourt would be and the money they would be paying for it. Fans would probably burn the stadium down
Greg Monroe is a FA, but they're also trying to unload Josh Smith at the moment. And depending on who and what kind of salary they take back (assuming they move him), unless they get a PG in the deal, they will still be short a PG either to start, play with Jennings, or play back up. Anyway, Detroit's situation could improve with trades depending on the returning assets, but as of the moment they're not going to go to the regular season with a back court of Brandon Jennings and nothing else.