It is legitimate to discuss IDN in this context, as the Term mainly throws up results from countries where Latin Characters are not used. As half the World use languages and scripts that will depend on the use of IDN for navigation, which is currently virtually impossible for most they will crop up again and again. Get used to it. This is the reality of a global internet. English Dot Coms will soon be regarded as a special case.
Without IDN the Japanese are getting by, using Search and Bookmarking. They basically just do not use the address bar to navigate. How often would you use the address bar if it only resolve Japanese Characters?