Saw a YouTube video other day of a UK restaurant offering a sandwich which was a piece of fried chicken (like KFC etc) with some cheese and bacon inside a doughnut. The guy making the video reported it was horrible and he'd never have it again. But demonstrates it's not just the USA.
Presumably restaurants need to keep coming up with new things. If a restaurant has some doughnuts some chicken/burgers and some burger fillings it makes sense to say well let's try putting them together. It either it sells or it doesn't.
If people like it then fair enough. If it doesn't sell it'll be off the menu.
