Well I for one very much enjoy a bar of Dairy Milk with Turkish Delight every now and then. I also loved the Wafer bar and wish they'd bring it back. I love the bubbly - I like it better than Wispa which seems to burn the back of my throat for some reason. I don't care what they call the bar - I am interested in the filling! Bacdk in the 1950s and early 1960s, Cadbury's did a range of Dairy Milk bars with a whole range of fillings - whole nut, fruit and nut, soft peppermint and fruit cream fillings such as strawberry, tangerine and pineapple. These were very popluar and I think the soft cream filling ones only disappeared because of production costs.
Bars these days cost so much to launch - what with millions spent on marketing and getting the bar in fornt of the consumer (big stores want financial incentives to give them shelf space) and the costs of setting up factory equipment to produce the bars - a huge volume of sales is needed to make the product viable so it can appear to fail but actually be very popular.