Clotted, the question is who should pay for inefficient flight scheduling practices, the operator or the pilot. If the operator wants to have one or two services a week, there is a cost. Who should bare it? MDC protects the pilot from sitting in a hotel room at the operators pleasure for most of his monthly roster period, returning home only for his designated 9 days off a month. Some operators attempt to call the days away in the hotel as "day off" to be deducted from those 9.
Do you think it is reasonable to spend most of your time away from home doing nothing, & unable to do anything about it - effectively unpaid? Pilots don't like inefficient flying. They want to do their work as efficiently as possible and go home to their families, like most other people. If they cannot be rostered efficiently, this is the operators issue & they have to figure those costs into their budget.