As a former college student.
My Dean who also happened to be the professor/teacher of my major explained in simple terms to me once the following.
There is waiting list for this class- either be on time and prepared or drop the class.
It was disrespectful on my part to be late, not show up or be distracted- even though I was paying my money to take class.
A life lesson that more should learn. When in the working world the employer does not need an unprepared or distracted worker.
Also it is encumbent on the employee to show up on time and ready to work.
In todays economy— more students could benefit from my life lesson.
There are many waiting for a job- if I choose to not show up, turn in substandard work or be distracted there are many waiting in the wings to take my place.
Every now and then when the oil patch is flat, I'll take some temporary work to help fill the gaps.
One such job had me working at a warehouse, and one of the guys I worked with was impressively competent, a go-getter, and frankly, what we'd call a 'stud hand'...with one exception:
He was ten minutes late every day.
We were talking one day and he was grumbling about not getting a raise.
I said "If you want a raise, all you have to do is show up fifteen minutes earlier than you have been, every day. You have the rest down cold, but I heard the owner grumbling about you being late and that has blinded him to the rest of your capabilities."
I'm happy to say he took my advice, and had the raise within a month.
Be there when you are supposed to be, be ready to do what you are supposed to do, and you'll do better at most anything.