I notice that you have perverted the meaning by adding the word "ineffective" which was not in the statement you are replying to, though you imply it was and that teachers are.
As if the only way a person can be overworked is by not being effective at their job.
And thus it is the teacher's failing that they cannot keep up with the workload, not the people assigning the workload.
It seems you have had a very rare and fortunate life. I am happy for you, though I wish you had more respect for others.