I think it would help if more people understood the time demands of teaching a course (neglecting other faculty duties, just looking at the teaching component). Many people have seen it only from the student side and not the instructor side.
From my experience, teaching a 3 credit course (meeting MWF for one hour each with no labs/recitation) requires the three hours for the course plus the following:
1. an additional 1 to 2 hours per class of prep. time to get yourself situated for that paricular class
2. 0.5 to 1 hours of meeting with your TA regarding grading and what is being covered in the course this week (more if the TA has a recitation session)
3. 3 to 5 office hours for students (of which a majority is not used, but still must be set aside)
All together, teaching a three hour course takes about 10 hours a week on the low end. Dealing with cheating students takes time from every portion of this 10 hours. You must waste time in class addressing the cheating. You must waste time in preparation thinking of ways to stop the cheating. You must waste time talking with your TA about the cheating. You must waste time dealing with students who will admit to "working together" but never "cheating" during your office hours.
The most important part of this, and the part that gets eaten up the most, is the office hours. This is where students should come to delve deeper into a subject or clarify material. Dealing with students during this time sets back students who truly have an interest in the subject and cripples students who have fallen behind (which will most likely lead to more cheating!).
While 44 hours over a semester sounds like nothing to most people, it is actually a significant amount of time wasted for the class.
As an aside, many students think that teaching is a faculty member's first and foremost duty. Depending on the school, this can range from absolutely true to downright false. Most schools have a layout on what they expect from their faculty regarding research, teaching, and service. Most schools weight that in decreasing priority as listed. If a school is well-known for its research, chances are it follows this pattern and teaching is not a priority for the faculty outside of good student evaluations.
Edit: A course at my school lasts for approximately 15 weeks which comes to ~150 hours per semester at 10 hours per week. At 44 hours, dealing with cheating would take 30% of my time spent on the course during the semester.