Answer:
Well, in most cases homework is assigned to help you see what you have learned after the teacher has taught you the lesson. So they can see what you may need help in.
But it does cause most students to become:
stressed
anxious
overwhelmed
frustrated
and can be very tiring after a long day of school.
You can also mention something like :
how they may need some time just to take a break from long hours of work after work.
or make a short 1-2 paragraphs mentioning how students are more likely to dislike school when handed more work than needed when heading home and so on, such as homework. Depending on how long your essay needs to be just pile on facts on why YOU think homework shouldn't a l w a y s be good for students and make them into statements, if I were you I'd add some benefits but add on with cons to show it most likely wouldn't help us out so much if that makes sense. So your whole essay doesn't seem so negative.
Hope it goes well!