Any country that has a global, taxpayer funded "authentic" national food police organization doesn t get to define the foreign foods it adopts as "normal" or "just our style". https://youtu.be/UnnOj-v8Iig
You can t have it both ways, no matter how many orient fetishist white folks allow you to think you can. And don t even get me started on Japanese style "pizza".
As with many of these things (like the preponderance of cheap white bread with little to no fillings or toppings) it s more of a cost issue than a style issue (poor individuals/rich country), no matter how much you try to dress it up as style.
Tuna, corn, and mayonaisse are all cheap ingredients (mayonnaise is oil and eggs, eggs are one of the cheap foods available in Japan), and they are 3 of the main toppings in Japanese "style" pizza and cheap,poofy, white bread.
Tomatoes, cheese, and meat cost too much in Japan, therefore they are scarce in starch based foods. People just spin this as a positive, because that s what Japan habitually does with negative **** about itself, (and for the inveitable "every contry does that" reply, another popular tool in the toolbox of defensive, xenophobe, apologists) and with a greater degree of marketing success than many other countries who have a more open media and public debate about, well, everything. It s more difficult to bury naitonal dirty laundry in such an environment.
Fukushima is not "a global disaster", it s "exotic Japanese Style Nuclear Management". And then labeling things thusly places them into the magical category of "culture" and therefore beyond the range of objective analysis and merit evaluation. It s a trick they ve learned well (See the modern phenomenon of industrial whaling cast as "ancient village culture" and "scientific" research).
I would venture to guess that the bacon thing is a production cost issue as with many so-called food "style" issues, and people s acceptance of yet another inferior food product under the banner of "unique, special, magical elfin Japanese culture" perpetuates it s existence.
I ll agree with you that most sushi in the US sucks (although some of the more unique creations I ve had in relatively authentic Japanese restaurants in the US were quite good http://en.wikipedia.org/wiki/Spider_roll), if you agree not to rush to the racial/cultural defense of all sucky versions of foreign food in Japan.