It’s pretty “popular” in United States also, well at least in my group of peers whenever we’re going for sushi one of us will have ordered katsu curry.
My absolute favorite is the curry as it’s made by Yayume sushi in San Ramon.
Sure, in america you might have a hard time finding a restaurant that serves both cheese burgers and american style spaghetti w/ meatballs. But when abroad you might find an 'american restaurant' that has both on their menu.
I think it's just down to people starting a 'foreign restaurant', there may just not be enough market for a specialty foreign food so you pack in a few popular dishes together and run a 'foreign country restaurant' instead of just a specialty place.
Certainly even in my corner of america (the pnw) where sushi is quite popular, we have a mix of places that just do sushi, or most do sushi and a few other dishes, or just a 'japanese restaurant'.
Sure, and in japan you might find the japanese equivalent. The basic argument was though that you find these ultra specialized places mostly within the country of the foods origin and that they are more common than more broad places. Which I think is a worldwide trueism.
I suspect it's because in the US, it all gets lumped together under the "Japanese food" category. I suspect the dishes being foreign in origin makes people less likely to consider them as separate categories.
I can confirm that I have the same thing in my part of the US though. A lot of restaurants will offer sushi and ramen both on the menu, with some other dishes like katsu curry showing up here and there. I would say the best sushi/ramen places here do specialize (just like you said about Japan), but it's pretty common to see places which don't.
Is this unique to certain genres? Everyone in the UK knows about "Chinese takeaway chips" and "Indian Omlettes", but you don't see such concessions in Thai, Italian, French etc. places.
Almost without exception, restaurants in the US that specializes in fish will have non-fish options, because there's a sizeable minority that will not eat fish at all (or at least anything still recognizable as fish).
Quite a few people in the US have an aversion to eating raw meat, including sushi. Any mid range restaurant is going to offer more than just sushi so that there's something for everyone when a group wants to go out to eat.
Heh, it probably would have been more shocking a generation or two ago. My mom liked to joke that her mom would overcook pork chops so badly that they would shatter if you dropped them. She was terrified of trichinosis, probably at least partially justifiably so.
In fact, I'd never even heard of eating pork as anything other than well-done until I saw Gordon Ramsay cook a pork chop medium rare.