I find that strange because two of my favourite chocolate products, Tunnock's Teacakes and Tunnock's Caramel Wafers have not changed their taste, consistency or even their wrappers in at least forty years and yet they are enormously popular. Tunnocks actuall trade on the notion that their products do not change!
In the 1970's I remember that the Tunnock's Caramel Wafers had a yellow fondant layer in the middle, now it's all just wafer and caramel. Also, in the 1970's the wrapper said "More than 1,000,000 of these biscuits are made and sold every week" - what's the number now? I think last time I looked it was 4,000,000.