There might be times when you want to have a simple quiz contained within a presentation, but not want to use Quizmaker or the Learning Games included within Articulate. One reason for this might be to maintain the same style as the rest of the presentation. Another reason might be if you are asking them a question to get them to think about the information being presented, but don't need the capability to grade their answer.
You can also use this same methodology to allow viewers to select what part of a presentation they are going to view. The same sales presentation could have a section that focuses on product features for the average audience, along with a more technical section for engineers. Branching the presentation allows the viewer to see only that part of the presentation which matters to them.