The Barbary Coast has a truly unique flavor that, while it may not be to everyone's liking, is the reason to give this interesting cocktail a try. The sweet ingredients create a smooth, creamy base while the gin and Scotch add the character the drink needs for balance. Without the characteristics of those two ingredients the Barbary Coast would be boring and just another overly-sweet drink.
One thing that I do recommend is to use a Scotch with a more subtle character like those from the Lowland or Highland regions. Any of the heavily peated Scotches will be too much of a contrast to the gin in particular.