Oh yeah, it's absolutely a very interesting period in Japanese history and if Cruise's character was used as a symbol of the fear of westernization of Japan post Meiji Restoration, that would be cool. Most of the criticism revolved around Hollywood's habit of using western actors to tell other people's stories. Samurai being is own plural form is just a happy accident that makes the jokes easier.

But he was just there as a big name for box office draw, and probably as an excuse to ditch a lot of subtitles. If I'm inclined to be ungenerous, I have a few other suspicions as well.

It's kind of like Kundun vs. Seven Years in Tibet. It's as if a studio executive said "Yeah, that's a great story, but let's stick Brad Pitt in there to put asses in seats." But at least with the latter, it was based on a book written by the real life traveler.