i agree completely, 100%. you have the right mind set on the situation

Then they can talk to their teacher if it is truly that important that you couldn't finish your homework, they will understand.

yes but if you are a student you is continuously missing assignments how will you learn your lesson?

yes, i feel that being forced to attend an asi is a very reasonable and fair punishment. Its a responsibility that you didn't take seriously, and you should learn your lesson. It will teach you to get things done the first time, to have responsibility.. You would never truly learn your lesson if you don't get punished.