Hershey's is truly disgusting, but do not get me started on the absolutely unjustified reverence the Brits have for a mediocre-at-best chocolate like Cadbury's...
Cadbury's has never been treated as anything other than a "chocolate for the masses". It was however, a pretty decent middle-of-the-road chocolate. Until it got bought out. Now it's shite.
Cadbury's has always been the sort of standard cheap block in Australia for my whole life (I'm in my 30s). Nobody ever considered it especially good (though having tasted Hershey's chocolate it is better than that), but having said that it definitely used to be better than it is now