I start by saying that this is certainly an opinion piece. However it’s not just pure opinion. My opinion on this subject is backed by a mathematical analysis of hashing algorithms. There are certainly some complicating factors that may be argued to influence the described scenario in all reality. However, given that I believe the core logic holds, a strong argument may be made against the use of B/S-crypt.
Source: Why You Shouldn’t be Using BCrypt and Scrypt, an article by Ben Prime.