It’s not that any treatment of the subject is, it’s that all the treatments are. It’s theoretically possible to make a holocaust movie which isn’t a preachy pile of collective guilt, but nobody will ever do it, because the only time anybody decides to make a holocaust movie it’s because they want to make a preachy pile of collective guilt. As for why to discuss it why not, or why discuss anything, take your pick.
Do you agree with the school of thought at the time which stated that Spielberg made the film solely to win awards and it was a cynical and offensive exercise?