I don’t think we should ever give up arguing against an obviously discriminatory practice, just because it’s “the way they are” or because it’s “the way Mark and Matt both feel”.

Ok, but in the same vein, I don't think it's good to spend all your time and energy on something that is not detrimental to the WordPress project in it's entirety. This guideline will not bring the project to its knees. All I'm saying is that Andreas has an argument that's been heard by both Mark and Matt and nothing has changed. Personally, in the extreme measure of this entire post, the theme repository and the back-end of WordPress provides the same opportunities as plugin authors to give credit where credit is due without a link on the front-end of the site.

Just seems like on an issue such as this one, you and Andreas are going to have to muster up a pretty strong group of vocal people who feel the same way regarding the guidelines and hope that change happens because of it. Let me email Matt and point him to this post and a few comments and let's see if he chimes in.