It has passed me by as well. I've been living in one of the largest cities for my entire life and have never batted an eye. There's just as much of every other cuisine as there is katsu curry.

I could probably make a 'The x-ification of Britain' for quite a lot of food items. Majority of brits in the comments echoing the sentiment.

Also, that site should probably do something about the botted comments?

Yeah. I've seen it in Wagamamas and other places that serve Japanese-inspired food but not noticed it in many other places.