I would like to make an observation after comparing the 2 products. Hosting for DNN can be quite a bit more expensive than Joomla on a feature vs feature comparison.
For the "average" user, like those wanting to host websites containing personal, family, self interest groups, etc. it will on average cost you more to host with DNN. For some reason most discount hosts will also restrict disk space, DB quotas, and bandwidth compared to equally priced Linux hosts.
I have DNN running on an intranet, but for personal use I went with Joomla because the hosting was more affordable for my usage.