There is a similar issue with the photographs produced by various organisations: these organisations would allow commercial use for e.g. informations, encyclopedias, education, but not for making advertisements.
In some instances, this is a case of protection of image: they don't want their image to be associated with products or political campaigns without their authorisation, and it's much easier for them to act on grounds of copyright infringement than on other grounds (especially since in some cases they cannot claim trademark protection).
This will probably have to be addressed in a satisfactory fashion. Currently, we deal with such images by allowing them on some Wikipedias (en: in particular) by claiming "fair use". However, many projects don't allow "fair use", though their communities would perhaps appreciate being able to use such images.