Why does TRL necessarily have to have a plot?

Rating: Null/10 (11 March 1999)

I don't see how you can criticise TRL for having no plot. It's intended to show a small slice of one part of a campaign to take a hill on one island in the Pacific during a war which lasted 6 years. Depicting the war in this way is far more realistic than an action packed extravaganza of explosions and heroism (like Saving Private Ryan or something like The Guns of Navarone). For the average soldier the war would have been remembered in terms of vivid images of small battles, not as any particular timeline of larger events.
In any case, TRL is the best movie I've seen for a long, long time.