So hanging is relatively new? Refrigeration's only been common about 100 years. And even at that, I don't know many farmers today that have fridges big enough to hang a cow or pig.
Cold weather is nothing new, hanging meat was traditionally confined to colder countries, in the ME for example they don't do it but rather either slow cook or slice meat thin and cook fast for tenderness.
Putrescence is a function of bacterial growth and digestion of the meat, hanging is a function of lactic acid breakdown of tissue and connective fibres, two wholly unique processes.