What's wrong with using Mailman? (Okay, I can list a lot of problems with Mailman, starting with its password policy!)

Does the use of a piece of software (software that's really not the point of the project) written in a language of which you don't approve somehow diminish the validity of the project? Parrot.org runs on a Drupal backend, not because we can't write a CMS in a language hosted on Parrot, but because we get free hosting from OSU OSL which we don't have to maintain.