Many well meaning people will often praise an ethnic restaurant as being "authentic"--i.e., true to the actual cuisine of a particular country or region. Somehow, "authentic" offerings are seen as being of higher quality and more desirable than the ones that have somehow "sold out" or "caved" to the tastes of the masses.
Authentic may be politically correct, but does it actually taste better? Granted, in some cases, authentic restaurants may go through more elaborate preparations that restaurants that seek to reduce costs opt to skip. Perhaps they would not have been able to get away with this "back home." I am not in favor of mediocrity. I just refuse to be against innovation and improvement as a matter of principle. The dinosaurs died out for a reason. So will many cultures that refuse to learn from the American way. (And our culture could, too, if we are not open to innovations from the outside).
Certain individuals maintain an adamant sense of superiority that they can "hack" the "real thing" rather than having to resort to something that has been "watered down" to meet sissier Western tastes. I am the first to agree the reducing the spice on Indian food is a pathetic accommodation to those who can't handle truly hot food. Other adaptations clearly make more sense, however.
There are large variations in taste around the World. Tastes are to some extent acquired; we "learn" to like certain foods that we have grown up eating. (There is also an evolutionary predisposition toward a preference for sweet and fatty foods, a remnant from times when it was in the interest of survival to maximize caloric intake while food was available). To the extent that changes have been made to dishes at "inauthentic" restaurants, these may, in fact, better accommodate the tastes of the vast majority of consumers in the "target" country. Yes, it looks like American foods are being messed up in other countries when they add all sorts of yucky ingredients to the real thing, but it unfair to expect people who have grown up to like yucky stuff to appreciate unyucky alternatives. There really is no reason why the Japanese should eat American foods sweeter than they prefer just to stay true to the American origin of the fare. Neither should Americans be subjected to a limited assortment of toppings for a food item just because people in country of origin didn't feel as much of a need to satisfy a desire for choice and individual differences in taste.
Some purists may feel that fusion cuisine is heretical and somehow uncultured. I have no problem if they want to stick with the "authentic" thing, but I am not impressed by their commitment to principle and their snide insinuations that they are more enlightened. Innovation and adaptation are cool!