I think the issue probably comes from tourists purchasing their favourite snack bars, such as a KitKat or Mars, age being unpleasantly surprised. Here in the UK

I think the issue probably comes from tourists purchasing their favourite snack bars, such as a KitKat or Mars, age being unpleasantly surprised. Here in the UK, I love these chocolate bars - definitely nothing like candle wax? This extends to more than just chocolate though. The Big Mac using mechanically recovered beef would be a big unpleasant surprise (which doesn't happen here except for the nuggets). Mix that in with cultural differences, you have plenty of horrors (I've heard egg mayo is blended in US rather than mashed together so it's chunky, which has horrified many a Brit). However, anywhere worth holidaying has great food to eat do I don't think it's fair to say its 100% bad. In my opinion, the bread in Spain sucks (unless fresh) yet I've eaten at many great restaurants and bought great snacks.