You two should hook up, get your slippers and your smoking pipes out.
"They are doing it to line their pockets"!
I clean all my Windows for free, I just don't like to think of anyone having a nasty, light related fall in their home due to a build up of grime and dirt on their Windows.
You plum.
It's not patronising. People, do fail these courses. They're a bench mark to reach that let's woolen know you work to a standard. My workload has trippled in 12 months, during a so called recession, in no small part I am certain, to having this qualification.