I mean...he's obviously not an elite player, but was voted to the All Star game. He's rated just where he needs to be.
I don't think people selected to the ASG by coaches etc, and NOT by popularity, can be considered underrated.
I think he's somewhat underrated, just in the sense that he's not as atrocious a defender as his numbers suggest when he's playing his proper position. He gets abused at center (where he's always played too many minutes), but at PF I think he's just below average. You could definitely hide him in the right system (e.g., if you replaced Boozer with Lee, I don't think Chicago would have any drop-off defensively). If David Lee is your primary rim protector on the floor and he gets killed, that's not a failure of Lee's, it's a failure of coaching. As others have said, everyone knows what a good player he is offensively and on the boards.
