One can surmise that reducing to a single multi-tasking ATC controller at supposedly quiet times is purely a cost saving issue. As has been mentioned on many issues over the past decades there will a point where cost saving starts to impact on safety. The skill in risk assessment application is balancing the cost savings with still providing an acceptable of level of safety. We've all noticed over the past couple of decades how many items have been dumbed down: e.g. reduced reporting times with self briefing; the self-help printing of nav' plans, NOTAMS, weather etc., the removal of crew apron transport = longer times from crew room to a/c all causing less time for in-depth flight preparation, reduced turn-round times = expedited flight preparation for following sectors, reduction in number of licensed engineers, ATC controllers on multi-frequencies, reduced pilot training and SOP's that dilute pilot handling skills, reduced experience for command upgrade, etc. etc.
I wonder if the industry is close to tipping points in some areas. I wonder if TEM & risk assessment techniques are being applied to supporting links in the chain in the same way we are taught to apply them in the cockpit. I wonder if the bean counters just go-ahead with their scalpel un-supervised until it becomes obvious that there is too much bleeding as the fat has been cut to the quick?