Research Madness

What's the problem with the standard college-level research paper? I believe that one of the many answers is this: students simply do not have the knowledge to do a full-fledged research paper without using an excessive amount of sources, especially if the instructor is the one who provides the topic. If a student is assigned a topic that he/she has no knowledge about, the most they could do is find a number of sources and elaborate on each one. Taking into consideration the average knowledge of a college student and the typical length of a research paper assigned by a college professor (10-15 pages), this leads me to the conclusion that quite the handful of sources have to be used.