There is a huge difference between those who have to fly and those who fly for fun.
As a Captain I cannot turn up and say to my PAX sorry guys had a tiff with the girlfriend so we are not going you would not last 10 minutes in my organisation.
its the same with the remnants of a cold or other things where you would rather not be flying. There are pressures to fly especially if you cannot find another Captain to cover you. Many of us flying freelance having other positions which can make it hard to get cover from your regular pool
So while your student has the luxury of only choosing sunny days in more than just weather related! working pilots in small operations do not have that luxury.
As in this situation the more reason to fly two crew as FOs of different capabilities are easier to come by
Pace, but isn't that the point?
So you are admitting that you fly when, under the terms of the legislation, you are not fit to do so?
As one who has flown over 40 years commercially I understand those pressures, of course.