Kwai not?

Prompted by a discussion with a friend who is doing some volunteer work in the Kanchanaburi province of Thailand, I just watched the movie which (for Westerners) made it famous - Bridge On The River Kwai.
This film won the Oscars for best film, director, actor, screenplay, music and editing in 1958 (and numerous other awards).
Yet, watching it, the plot is extraordinary. The first half hangs on the right of British officers not to do manual labour, while enlisted men are marched off to work. This position is supposed to elicit deep sympathy, and when the Japanese finally back down, the enlisted men rejoice. Maybe I'm naive, but I find this not only historically unlikely but also even unsympathetic in 1957.