Mark Ritson: The Diet Coke relaunch shows its marketers have lost the plot

Up until now the general consensus has been that, while Coca-Cola might be in bit of trouble, its marketers were one of the major reasons to keep the faith and assume they would steer their company through the tough times ahead.
There seems little doubt that Coca-Cola (the brand) is starting an irrevocable decline as global tastes swing away from sugar, artificial sweeteners and fizzy drinks. Coke will always be Coke but it will become a fraction of its former self in the years ahead. That&rsqu