1) He's a restricted free agent, so Milwaukee can match whatever offer is sent his way.
2) He's kind of a waste on a roster with Terry, Crawford, Bradley, Rondo, and Williams all fighting for guard rotation minutes.
I'm a Jennings fan. I don't think he was ready for the Iverson-Lite role that Milwaukee asked of him in their Fear The Deer playoff run, and I don't think putting him on a roster with Monta Ellis does him any favors (because they're essentially the same player, but Monta is much more of a professional/tested product). Unfortunately, it appears that his 55 point game will be a spectre over the rest of his career.
Now, if we didn't have Terry or Crawford, I could totally buy into him as our microwave scorer.