Whats the point of Finals..?

So as a junior in high school, like previous years, with the end of a semester brings another set of final exams. Its often debated if around a quarter of a student's grade should be measured on 90 minutes of tricky multiple choice questions and rushed essays, testing time management rather than knowledge.

The fact of the matter is that in the real world, you are nearly never given an hour to complete a task and no longer do you have to crank out an essay that you end up regretting what you wrote right after leaving the testing room. If you cant
 
A semester grade, in my mind should reflect overall performance. This means that if you have one bad test or assignment, it shouldn't affect your overall grade. Who knows, you could have forgotten to study, or just been having a bad day which leads to you not performing at your best during a test.

It seems as if teachers don't like to give out finals also. More often than not, teachers that I have had in the past seem to dread grading finals and would rather just give a multiple choice test to make their job easy and so that they don't spend a bunch of days grading exams.

No one likes taking finals. It is very stressful for the students, and sometimes annoying for the teachers. I think that final grades should rather be taken into account of a semester of the student. Participation seems to directly undermine assignments and final grades tend to only reflect the work on tests, which accounts for maybe one day every two weeks of class work.