Jeta1 - you took the words out of my mouth.
All the theory (and practice) says that accidents are not just caused by one thing but a "series of events" - aka "the error chain" or "poor judgement chain".
I think the vast majority of aircraft commanders are sensible and assertive enough to take whatever fuel they deem is safe and sensible. On certain occasions this might be flight plan but, in my opinion, to plan to operate to busy places such as LHR on min fuel on a continual basis is courting disaster, eventually.
------------------