Well, being an early adopter of this framework, I'm really confused as to why DNN is being compared to Content Management Systems.  I don't remember anyone advertising DNN as a CMS, it's an application framework.  CMS solutions should have workflow built-in, of course DNN doesn't so that one point would be vexing to anyone expecting DNN to work as a CMS.  I suspect that's why the banner on the DNN Home page has in big bold print the following:

DotNetNuke® is the most widely adopted open source framework for web content management (WCM) and building web applications on Microsoft ASP.NET

A Web Content Management system is not the same as a CMS.  If you examine the framework, it offers a lot of flexibility, and scales from small users to larger users needs.  Yes, there are issues, but I've been in the software / IT world since key punch machines were used, and I can tell you nothing I've ever come to use in the many varities of systems works completely devoid of issues.  That's why folks in IT are still needed.

The fact that DNN has modules which you are free to modify to include whatever is missing is something that is a positive, not a negative.  The thrust of the Core modules have always been to provide basic functionality, which allows other developers to build upon.  While my approach has always been to use the Core modules rather than 3rd party modules is by choice - I'm cheap that way.  The existence of enhanced 3rd party modules underscores the proven strategy that allows DNN to continue to be a leader in its' niche.  Now, if you are a really enterprising developer or have money to do it, you could transform the existing DNN into a CMS, adding the missing bits, and that says something about the flexibility of the framework.  Add the fact that DNN is freely available, and the license allows it to be modified, and all the other features, makes it valuable.  The adoption of the DNN framework globally suggests that folks around the world value it.

I personally, don't care what is used by anyone, or what a client wants.  I deliver the goods in the fashion that the client needs.  Of course, I offer my opinion and advice but in the end, it's the client that matters - they pay the bills. As a consultant, user, developer, or agent, the choice is yours to make based on your circumstance. 

I think the idea is to specifically tell you that there's no license. This way you are aware of this instead of just bypassing it.

Still a 4-5 page install wizard to a bit too much just to display information about the package. I posted about this when 5.0 came out. Maybe a longer single page would have been sufficient. Or the reasoning is that if the page is too long, a user won't read it.