JXK - I don't think that is the case. Take a look at the earlier example about the economics of raising the price. It is not difficult to absorb.
The issue revolves around how FI's are paid as well. Most get a very tiny retainer and flying pay. They majority don't get paid for the briefing time in a 2hr slot and so this is an area where the standards suffer I think. The motivation is to get into the air as quick as they can so they don't lose any precious hours or flying pay often giving lip service to the briefing. This is exasperated by students turning up late, previous lessons overrunning etc.
The briefing is an equal part of any flying lesson and as such the Instructor should be paid properly for this time.