Minority Report review.
I think the main reason you can't have the downer ending in Minority Report is it would completely undercut the moral of the story.
I see what you mean and it makes sense, I just like the thought of Spielberg pulling the rug from underneath the feet of the audience. Also, while the moral of the story works fine given how it all ends, the real world often tells us that 'morals' and happy solutions don't always apply in 'the system', so I think using the sadder ending actually would have worked too. Yes, yes, 'it's a movie, not reality'...I know that, I'm just saying the potential was there. I see the downer ending as a message of 'If we don't wise up now, look at the crazy shit we'll be doing later on.'