Why is the absent Consultant to blame?

I see this has been in the news again. Last time I was in a hospital at the weekend, there were fewer numbers of everyone around - nurses, physiotherapists, junior doctors, laboratory staff, cleaners, canteen staff - you get the picture! So why is it being assumed that it is the absence of a permanent consultant presence on the ward that leads to a higher death rate at weekends? Are we really the most important person in the hospital and should I not be so self-deprecating?
One has to accept the findings in recently published studies that death rates are truly higher, even after correction for a number of possible confounders. The phenomenon does indeed need investigating but plans of action need to be put in place AFTER we know exactly why it is that a patient is more likely to die on A Saturday or Sunday.