a question on public access to higher res images

Just starting to check out animation festivals on the web. Already one thing strikes me as a question. Why is it that a site like Spike and Mike that has a cafe press spinoff set up and most do not? Just as an idea I have in mind some funded public organisation with loads of images, some as paintings stored in a basement. They have had lottery funding to do some scanning but only low res versions are ever found on the web. There is no viable business case for making them more available as it seems. So something like cafe press would be very useful for organisations that find it difficult to package up a CD or whatever. Not getting at anyone. Just a question. Why do public bodies not put more high res images on the web?