I've operated into SY and BN thousands of times and to suggest that any pilot who operates regularly into these (or any other for that matter) ports doesn't know their responsibility for fuel and have backup plans in place, has very little knowledge or respect for professional pilots.
While I have never held for longer than indicated by the WX/ notam, I think the point trying to be made is that if ATC can't process aircraft within the time indicated on the traffic holding notam, issue an updated one. Also pretty simple really...