Having been both a teacher and a student - the former up to a pre-varsity level and the latter to an undergraduate level - I would say the problem lies with education system flaws that compound the issues found with both students and teachers, which I have listed below:
Students
- Laziness
- Poor discipline
- Poor work ethic
- Unrealistic expectations
- Lack of drive for success
- Apathy towards themselves as well as others
- Lack of respect towards teachers
- Lack of curiosity
- Entitlement mentality
Teachers
- Laziness
- Poor discipline
- Poor work ethic
- Unrealistic expectations
- Apathy towards students' problems
- Lack of respect for students
- Lack of creativity and flexibility
- Lack of knowledge on their subject(s)
- Lack of passion for their subject(s)
These issues are just listed off the top of my head, and the list is not exhaustive by any means. Notice, however, that I have listed a few things under both teachers as well as students.
The COMPONENTS of an education system - e.g. standardised testing - in themselves may be beneficial to students as well as teachers. However, if the system as a whole is flawed due to antagonism/inhibition between its components as opposed to synergism, then of course the results would be less than optimal.
For example, in my homeland of Malaysia, people complained that the standardised exams were becoming too easy, which was actually due to political interference with public education (politicians reduced the syllabus scope to raise passing statistics, etc.). To remedy this, the government - which was responsible for the problem to begin with - abolished them and replaced them with school-based assessment. The curriculum remained the same.
Our curriculum is weak to begin with, and while standardised testing as well as schoool-based assessments are both equally viable for a fair testing of a student's strengths/weaknesses, this one flawed component screwed the whole system over. OF COURSE you'd find problematic students and teachers wherever you look, so allowing flawed components to remain unchecked is the main problem, in my humble opinion.
That being said, it is naturally impossible to devise a perfect system.
Thus, it is my sincere - some would say harsh - belief that the system which produces the best results should be selected. And by 'best results', I mean the system should produce the most thinking individuals who would be beneficial to society as well as humanity. If along the way there are some failures, well, statistically speaking, there is always a wastage factor. Be it bad teachers, students, or just those anomalies in the system, it is impossible to have zero casualties, so to speak, so the aim in devising an education system should be to minimise wastage rather than please everyone.
The optimal solution hardly needs to be perfect, and mathematical logic is, for the most part, infallible.