Most of the responses are pretty reasoned and get to the heart of the matter: good player, but would be a great fit as a 3rd guard, a solid 3-and-D guy off the bench, and certainly an important piece on as possible championship team.
With that said, if you can get a dynamic scorer or playmaker at the SG position, you absolutely do it. Derozan, Beal, etc. Bradley just doesn't have those skills -- ball-handling, passing, playmaking, finishing at the rim, etc. It doesn't mean he's a garbage player, not at all. But he is what he is.