Jimmy-
As to why CC-ND (=No derivs) is bad, well, it's not GNU free. The right to make derivative works is an important right. It might be viewed by some as less important in the context of a photo or text, as opposed to software code, but I personally don't think so. I think it's very important in our medium.
Maybe, but there's another side. I've just tried to get permission to use some example webcomics on Wikipedia in the respective articles. I received one positive and three negative replies. The main problem was that people are worried about third parties modifying their work.
And I can understand that concern. If you have an example comic which features the main characters, someone else can easily rip off these characters and create their "fork" of the strip, even market it commercially, as long as it's copylefted.
What does it do for us to have it modifiable though? We're an encyclopedia, our purpose is not the creation of new artwork but the improvement of encyclopedia articles. The purpose of the comics is to illustrate these articles. Modifying them does not further that purpose (except for resizing, converting etc. which are probably allowed anyway).
I think there's an argument to be made to allow something like "no derivative works" for *some* images. It doesn't really hurt our purpose as a "free encyclopedia", IMHO.
Regards,
Erik