GingerK ... ITA ... it's not always the students that are the "issue" to a successful class, or a disappointing one. I too have felt as the outsider with the teacher-student clique ... and then too much reference to previous classes, inside jokes, and assumptions that everyone has the same background as the clique! (eg. this was taught in the previous class, etc.)
Also ... instructors that do not come prepared or are not qualified to teach the course ... have not read the pattern and notes since the last class two years ago ... do not have irons/boards set up and waiting to be used ... tell you to cut fabric a certain size, and then later say, oh sorry, that was wrong.
Yup ... all happened ... in one class!