I'd like to touch on something that this thread made me think of. It has nothing to do with your post Quix, its unrelated, but is more referencing the OPs...
TENURE! The attitude of some professors is deplorable, and whoever invented the idea of "tenure" is an ass. Professors are employees of the university, the university provides a service. The students are the paying customers, who are paying a considerable amount for this service. So, when I interact with the people who are providing me with a service, I expect them to be polite and treat me with respect, so long as I do the same in return. It really doesn't matter whether my question annoys them, I'm sure people in other service industrys get asked equally annoying questions, yet they aren't rude or disrespectful to their customers because they know they will be accountable to their boss's. That is the problem with tenure, it leaves these employees essentially unaccountable for their poor behavior, piss poor attitude, and unprofessional behavior.
It's also awarded very rarely, after significant service to the University, as well as significant *trends* in student feedback and publication. The tenured professors are the ones the University relies upon to set the overall reputation of the University via scholarship. Academic positions aren't like service industry positions, for a number of reasons - these are 7-day a week positions that are constantly changing and extremely cut-throat. There are some who abuse it, certainly, but that doesn't mean that the system itself is flawed. There is *a lot* more to academic positions than simply teaching, so it would be mistaken to do away with these kind of merit-based rewards. The tenure process still keeps the professors accountable to the University (it *can* be revoked), but holds them to a different (and in some ways, higher) standard than traditional student review. Bear in mind that your experience of the professor is one subjective data point in a larger trend - there will always be personality conflicts between professors and students; that doesn't always translate into the professor being the one to blame.
Every university should have a formal means to rank professors. Based on professor rankings at the end of the semester action should be taken: disciplinary, termination of employment, congratulatory. If a university doesn't have a way for students to rank a professor's performance throughout the semester the university is failing the student, especially if it doesn't act on bad reviews. So, at a school that is actively helping students, tenure will not be an end all.
There are formal means of ranking professors - they are the student questionnaires that all non-tenured faculty must endure. Action is taken based upon the reviews - the problem is that there is no means of feedback *during* the semester to address any problems, so any correction only occurs *after* the problem semester. This is why I have an open feedback forum for my students to let me know what problems they are having and how I can tweak the class to address them.
There is, however, a fundamental flaw in both the existent and the proposed mechanism - undergraduates have a marvelous ability to blame everyone but themselves for poor performance (part of an academic entitlement mentality I think we produce in primary and secondary education), so when a student performs poorly, there is an all-too-common knee-jerk response of "Well I'm smart, it must be somebody else's fault". I've had students blame me for them not showing up prepared for mid-term and final exams (and considering I provide study guides and am very flexible in terms of content and formatting, as well as holding three days of office hours, as well as online discussion forums, etc., etc.), or for them writing ****** papers, despite numerous suggestions, drafts, feedback sessions, etc., etc. If professors are penalized based on bad reviews, and the bad reviews are based on anything from legitimate poor teaching to an ill-prepared piece of furniture masquerading as a student, then there is something inherently wrong.
EDIT:
Oh, I almost forgot my personal favorite. I was given a horrible review by a student for having delays in responding for an on-line class I taught. My internet connection was spotty at best because my city was flooded by Hurricane Ike which knocked out service. I posted to that effect, made announcements about that, and posted pictures as evidence, but I was still portrayed as the bad guy.