>>So lay off us poor rosterers, lets have a go at commercial<<
I quite agree! I would never personally criticise a roster planner. We all work in jobs designed by others. The problem in an airline is that it can be very difficult to get information about crewing and rostering difficulties from the coalface to the boardroom. My experience is that, without a BALPA cc, it is nigh on impossible without sticking your head so far above the parapet that it is blown off completely.
If a really bad pattern of flights is assigned then it can take an age to get it changed. In that period a crew may really suffer and the general public are put at risk of a fatigues crew perfoming below par.
I don't know what the answer is; its just part of the industry malaise.