Brute force as an attack vector is dealt with by requiring "strong" passwords, not by using scrypt, so the thought of using a hash that protects all passwords e

Brute force as an attack vector is dealt with by requiring "strong" passwords, not by using scrypt, so the thought of using a hash that protects all passwords equally with respect to the time it takes to try one, as an extra layer of defense for those weakest of the "strong" passwords, doesn't usually come up unless you're actually looking into how to design a login system instead of just copying from somewhere/some book as fast as you can and moving on. This issue with Tumblr that late doesn't surprise me at all. At least one major benefit of SHA over MD5 is that you won't trivially find collisions and thus compromise the accounts of even those users with strong passwords...