Being a student means that you have entrusted by your loved ones to attend the class and to involve with any activites which are related to your studies scuh as going to the lab or mooting etc so that at the end of the day you will get a degree.
Getting a degree means you need to earn the degree. How? By going to the class . It is your paramount duty to make sure that you go to the class regularly. This is an amanah that you pledged when you enrolled at this university.
However, there are some students who are so busy with other activities at the expense of their classes. I have no objection if you want to involve in these curriculum but of course not to the extent of missing your classes. This should be in your mind when you agreed to involve in this area.
Lecture and tutorials involve you and your teacher. The teacher is in charge of the class, she is the managing the class and students. Hence, any student should not think that they can come anytime they want and miss the class anytime she pleases. An excuse letter that you have is not excuse for missing the class. It is just to inform the teacher that you have a program to attend to.
It is encouraged for every student to involve in these activities. They also must bear in mind that by doing this, they are sacrificing their leisure time for the sake of their activities.
I really hope that my students will think deeply before they decide to involve in this activities. But most of the times a communication that you missed with your teacher had actually made her upset.