It is worthwhile to distinguish between two possible goals in making a PowerPoint presentation-information presentation, in which the goal is to present information to the audience, and cognitive guidance, in which the goal is to guide the audience in their processing of the presented information. When your goal is information presentation, PowerPoint slides can be full of information that may be extremely hard to process by the audience. However, since your goal is simply information presentation, you are not concerned with whether or not the audience can process the presented information.
When your goal is cognitive guidance, you want to make sure that the audience members build appropriate knowledge in their memories. Your job is to communicate in a way that will have the desired impact on the audience, so you need to design your slides so they are consistent with how people learn.
In my opinion, many of the examples of misuses of PowerPoint occur when the slides are designed to present information rather than to guide cognitive processing. In short, like any communication medium-including books-PowerPoint can be misused as a device for presenting information without regard for how the audience will process the presented information.