It amazes me how many people get the most basic stuff wrong when making video tutorials. For instance I recently hit YouTube to look for demonstrations of a tape emulation plugin. There were quite a few, but virtually every single one of them was ruined by the narrator yapping incessantly over the A/B's. And the comments were full of people complaining about it!
Sonar suffers from a lack of official tutorial videos and a poor quality manual. It has a reputation of having a steep learning curve and being frustrating to use as a result. I remember reading a thread on an EDM forum some time ago where someone had asked "what about Sonar?" and most of the replies were along the lines of "it's good if you can work out how to use it." Kids are choosing DAW's like Abelton because it's relatively easy to get up and running making cool beats in part because there are so many more "getting started" tutorials which are easy to follow. Sonar's manual is in my opinion an error strewn mess - the layout is awful (you find yourself going around in circles and wild goose chases and clicking through multiple pages to get what you want) and parts of it are so utterly wrong I'd be surprised if people weren't rejecting Sonar at the demo stage because of it. It's so frustrating to go through the steps of a manual only to find that it's as if they're describing a totally different program.
Cakewalk might not "have the staff," but I can't imagine the newbie documentation side of things is exactly helping sales.