if we take a walk on the memory lane, PC shipment went down first, then notebook, and now mobilephone where as the same time when PC went down, notebook went up, and when notebook went down, tablet went up.
the same can be said about the situation on cameras. as maturity of technology is approaching to the point of diminishing benefit (for which the mass market has a wide tolerance, compare to the professionals who requires further tech development). the growth stalls and decline soon after. on the street we see more and more 2nd hand models since they are still usable; we still see iphone4 on the street, in other world the said phone is already approaching the bronze age. and in camera world stuff came out around 2009/2010 are still good enough for most people.
i suppose if we take a look at the economy we see a clue, people hang on to stuff for a longer period of time and i suppose the crisis stalled the growth of developing countries too, smaller growth in pie is unhealthy for business.