Astronuc said:
That's pretty much what I have observed, but that's more so the case than it was 30 years ago. While there is emphasis on grades, there is little emphasis on the hard work and learning that is required to achieve the grades. Teachers do catch it from all sides, shortchanged by school boards and administrations, little or no support or interest from parents, and indifference or apathy from students. Now it's not all students, parents or school boards/administrators - there are exceptions. There are some students who want to learn, e.g. the top 5-10% who take one or more honors courses, and the portion of parents who participate in PTA and volunteer in the schools, and the portion of school boards/administrators who do support excellence in education and other programs - but they are still too few - they are the exception, not the rule.
And the students are carrying those crappy attitudes about learning into college with them too. They think they can whine and weedle their way to a higher grade without any effort. No, not all, but it's more and more every year.
I was trying to figure out what was going through the minds of a couple of students today. They were camped out in the hall outside the office of one of the other faculty, and one was calling his office from their cell phone to tell him they were sitting outside waiting.

Were they planning to ambush him as he arrived back? I decided to take pity on them and inform them that he would not be back in the office until next Wednesday, because I wasn't entirely sure if they were going to just sit there all day waiting or what. I'm sure they'll be whining that he wasn't around at their beck and call to answer questions when they obviously hadn't planned ahead with as much as a phone call to inquire if he had time to meet.
I was fortunate to have many excellent teachers, most of whom taught the major works/honors and AP courses. In math and science, we learned the theory, not just crunching numbers. The math and science teachers were good friends, so the chemistry and physics teachers new what the students were being taught in calculus, and vice versa.
I was also fortunate to have excellent teachers throughout school. Only one stands out in my mind as an especially bad teacher...my 9th grade biology teacher. In the first progress report in the first quarter of the class, he recommended to my parents that I should drop the class because I just didn't have the aptitude for the subject

I've always wanted to track him down and pay a visit to tell him just how wrong he was. He was such a miserable teacher, and the entire class hated him. He just simply had a mean streak. If I didn't already have an interest in the subject before taking his class, that might have turned me off for good. I wonder how many other students were turned off biology by him.
One example that always sticks out in mind: we did some "lab" project with peanuts. I don't remember what the lab was, but at the end, someone asked if we could eat the leftover peanuts. To our surprise, he said, "Yes." So, while we were finishing up writing up our results, we munched on peanuts. He then went around the room and deducted a point for every peanut we ate, telling us we should have known it was against safety rules to eat in the lab! When we naturally protested that he gave us permission, he told us he said we "could" eat them, not that we "should" or "were allowed to" eat them. He had to take off about a month for surgery, and you've never seen students so happy to have a substitute teacher! Since it was an extended absence, we had a sub who really knew the subject, not just who gave us busy work, and we learned so much more in his absence.
Another example of how much of a jerk he was...my father died during that year. Our notebooks were due for grading less than a week after the funeral, and of course I had missed several days of school, so mine was not complete (notebooks included class notes, ungraded homework, etc.). He still expected I would have mine ready to submit on time. I still remember sitting at home, bawling my eyes out, scrambling to get assignments completed, and trying to get the notes I missed copied from my friends so I could turn it in on time. I got the thing done and turned in, but my mom still decided to call my guidance counselor about it (she was more worried I might be suicidal, which is why she called the guidance counselor rather than the teacher

...murderous maybe, suicidal no)... AFTER it was turned in, and the guidance counselor talked to the teacher about it, he came up to me and asked if I needed more time to work on it.
The only other teacher that comes to mind as I think about bad teachers was a distant second...he was our world history teacher who was just boring...at least once we got over the quiz on the first day of school. He graded it, gave us all the zeros we earned on it, and then told us he just wanted to confirm we were starting out knowing nothing on the subject and we'd all be able to answer those questions by the end of the year, and tossed the quizzes into the circular file.
I think the fact that the bad teachers stand out in my mind the most highlights how many good, great, and excellent teachers I had.
I wonder how many professional parents would take a day off from work and give a lecture in the classroom. I wonder how many school districts would encourage or accommodate such a program.
There's more to teaching than just taking a day off work to talk to kids about what you do. My AP biology teacher (the one in senior year, not the one I mentioned above) tried that one day with a former student who came back to visit. It was the worst class we had that year. I think our mouths were just hanging open in shock at how horrendous this person was at teaching us. The next day, our teacher's only comment was, "I guess I won't do that again."
There's one caveat as well to Berkeman's observation about people who work in the field teaching a subject. That part he mentioned about things becoming second nature or intuitive when you do them for a living can also be a drawback for teaching. I've been taught by professors who you could just tell were brilliant in their field, but who would forget that what is intuitive to them is NOT intuitive to the students, and needs to be spelled out step-by-step. On the other hand, the person I worked with for my post-doc is absolutely outstanding at walking people through each step of a concept. He does this both in the classroom and when giving seminars and talks at conferences, and even when training the people working in his lab. One needs to learn to teach as much as one needs to learn the subject they are teaching.