I would agree it means keep the aircraft over the extended runway centreline. That way you're in a position to accurately follow a SID. Also not considered yet is noise abatement which is taken into account when designing SIDs. I don't suppose the BAA or other airport owner would respond to a serious noise complaint by saying:
"Yes we are sorry you got woken up by the sound of jet engines Mr Nimby, but you see the plane got blown over your house by the wind so you really shouldn't be bothering us as it's not our fault!"
