And they don't do it semester after semester, which of course can be a bad thing or a good thing, but if anything surely hones an instructor's understanding of the student body.
right - that's sort of the point I was getting at, but not very well. There's a certain nuance to successful teaching that takes time to master, regardless of the subject material. Not everyone gets it, of course, but most of the instructors I've had who were really good at it were, in fact, older and more practiced instructors (across all disciplines). Using adjuncts to supplement gaps now and then is OK, but when a large portion of your staff is temp adjuncts, the quality of instruction has to be lower.