Just a few reasons why you might not want to pull 'right up to the holding point line' that I can think of. Strangely they are all due to
airmanship , that one quality that some are advocating as a reason
to pull as close as you can.
1. Aircraft in front at the hold in question. We pull up 'right' behind and get a cabin full of burnt jet-A1 fumes. Not nice for the punters, or us.
2. Uphill taxiway leading to the runway (D1 hold point short of 24R at Manchester springs to mind). You pull up at the hold point in a heavy 767 (or many other types I would suggest) and you need a great handful of thrust (above the manufacturers recommended limit) to get the ship moving again. Not nice for the poor old traffic taxying behind, free sandblast ready for repaint though.
3. Continuation of point 2. When ATC ask for us to expedite crossing, it can actually be quicker to start from the flat and get some momentum before going uphill to cross the runway.
4. Perhaps after the aircraft mentioned in point 1 lined up the crew were busy with a task that required the commanders full attention, and just perhaps he felt that it would be safer to remain stationary during this period.
So, no blame, no presumption, just a few ideas to counter the 'myth' that airmanship dictates that the commander should ensure that his aircraft is as close to the 'cleared' holding point as it can be. Certainly, on some occassions airmanship may mean that the commander DOES get his aircraft as close to the holding point as he can.......but there ain't no requirement for him to ALWAYS do so.
PP