Short version, the ABA equates the J.D. with the Ph.D. and also allows lawyers the right to use the title obtained by getting one, especially when working in an academic field (i.e. as an instructor you can be called Doctor). Small wonder when a J.D. takes 3 years and 90 units, but even this MFA one member was touting only requires 45; and all Masters programs require 45 units or less. I'd never use it in legal practice, but if I ever taught I might.
Okay, rant over! lol