Yes, and you just reminded me of something similar to the Marketplace… long ago I signed up to develop courseware for Microsoft’s Official Curriculum, where one can get trained on various technologies. It seemed like a great way to have a nice side income. However, the cut Microsoft took for listing the course on their website was astronomical, and it was taken from every student purchase. Quite a great way for a big company to make money, I thought, but not so much for me. Because the amount left over for me was not really worth the effort, I did not end up pursuing that income-making opportunity.
So, think about the perspective of the developer… it makes perfect sense that they would not support a product purchased from Marketplace because they are not making much money from it.