A guess - nothing more as I do not do anything like the long haul I used to - could it be that pax are now more likely to press the call bell? When I was first taken on a flight (aged 9 in 1965) I was told by my parents that the bell was for emergencies ONLY.
My view is that pax today see the CC as 'staff' and call them for absolutely anything - such as a cup of water - rather than go to the galley and ask for it and get a leg stretch too! If the CC know that pax are going to buzz for any and everything - they would be less inclined to patrol?
I wonder if Tight Slot (and other CC) could say if the number of times that pax 'buzz' has increased significantly during his working time? (Not asking for a view as to whether his airline CC patrols more or less) but about pax behaviour.