I definitely think that the Internet Archive serves a valuable purpose. However, they will not see any money from me until they crack down on all of the porn hosted on their site.
The project carries no Morality and that is a good thing. It will always archive content you agree with and content you disagree with and that is a good thing. Adult content is clearly tagged. Copyright is clearly managed.
Genuine question, if we were to sanitize all archives of porn, do you believe that 80 years from now, we would have a representative idea of how people experience sexuality right now?