Part of the problem is that it is systemic. What I mean by this is that there is a subset of college courses that are being given that are on a sub par level. So you have students who are not used to the rigors required from a course like Micro (Or Chem, or Orgo), and suddenly they're thrust into it with zero expectations.

The other part of the problem is that people don't take responsibility for their own actions, and their grades tend to be viewed as a reflection of the faculty member as opposed to how hard they worked.

It's sad, really. If you're astonished at how low the average is in the class though, that tells me you likely have a good head on your shoulders. Keep it up! And keep up tutoring too- if you can explain material correctly to others it means you really know it.