I am no fan of Hershey but I usually don't find it disgusting [1] but everything about Cadbury turns me off.
I knew someone who started her own artisan chocolate company and she was quite eloquent about how other chocolate brands do it wrong, particularly using lecithin as an emulsifier which simplifies the production process but doesn't give the best quality.
[1] Right now the thought of chocolate, peanut butter, shortbread cookies or anything like that turns my stomach even if I'm hungry because I'm tapering a medication which causes weight gain and dropped about 10kg in 4 weeks.