-People think that because he has stopped stripping guys in a full court press that his defense has "really fallen off, man"
I don't think he's "dropped off defensively", but I think two things happened:
-The rest of the league is adjusting to him, but he isn't adjusting to the rest of the league. Teams know that very few 1 or 2 guards can beat him off the dribble. Guess what they decided to do? Run him through screens. I don't think he'll ever be Tony Allen, but he needs to at least show some improvement in this area. It reminds me of Gruden's QB camp with Johnny Manziel: "Do you know any defensive coordinators?" "No sir." "Well they know you!"
-He is being asked to guard bigger guys, which he can do - just not quite as well as guarding 6 footers obviously. I would like him to punish those guys on the other end a lot more though. He's such a great athlete, he should just be able to run away from those guys
-Defense is still not given enough weight in player assessment.
This is the main reason I don't think he'd have much trade value. Regardless of the excitement factor, perimeter players need to have an offensive game to be considered valuable. I think this is an exaggerated belief that is based on reality - teams can't afford to have 1 bad offensive perimeter player unless he does something GREAT. If you have an offensive player who plays like Bradley does now, it allows teams to hide teams to hide guys like Damien Lillard and Steph Curry, it allows them to pack the paint, etc.