I see a new magazine has launched called SharePointPro. Are they really using dotnetnuke for their site? ;)
So what, just because you can - with loads of effort and money - build a site a on a certain technology (SharePoint), it doesn't mean that you should. They picked a platform that is much more fit for their purpose, a wise decision.
Did you know that SharePoint Overflow is not based on SharePoint? Outrageous! :-p
SharePoint Pro mag is part of Pention Media which does the Connections conferences (Dev, Windows, Virtualization, SharePoint, Exchange, etc) as well as publish quite a few different magazines, including SHarePoint Pro. The SharePoint folks would love to move to SharePoint, but as a company they are on the DNN platform.
Course I wish it was on SP as well, but I understand the reason it isn't.