I can only agree with you that pax seem to press call bells for the most trivial reasons, on one of my recent flights when we were all strapped in for landing, a call bell went off, we all looked where it was and as we could see the passenger sitting underneath was in no distress, so we decided not to act immediately, after we landed, when it was safe to do so a crew member checked on the passenger who was most upset that no-one had answered the call bell to collect his empty glass at 100 feet above the runway! On the 767 the call bells are located in the armrest and are very sensitive, all through the flight we find ourselves answering call bells to find that passengers had not intended to press them anyway, or even argue that they havent. In these circumstances we have to be careful not to become too complacent, after all we never can tell whether someone just wants a drink or really does need our assistance...