>I’m genuinely confused on why people like these kinds of movies, when there’s more upbeat inspiring movie flicks.

Being upbeat and inspiring does not inherently make a movie better, for me.

I experience stories in order to have memorable emotional experiences. These can also be from "negative" emotions (tensions, sadness, fear, being disturbed). I can look back on those experiences with nostalgia.

>most people just need a positive perspective to tell them that life isn’t that bad and we should help people realize that no matter your circumstances you can always rise up.

I'm sure plenty of people have watched Taxi Driver and thought to themselves something along the lines of "well, at least I'm doing a lot better than this guy" and/or "damn, we really need to help people like these", instead of "life sucks"