If the process is structured to lead to an outcome then the outcome is the primary purpose, even if the secondary purposes along the way may be more enjoyable. That's not to say the process isn't part of the goal, but to take your NCAA tournament example what meaning does the drama of the upset have if it isn't putting that underdog one step closer to a national title?
I hesitate to comment too much about the brackets because I was never involved with them, but if I understand right what you found most fun was watching and discussing more obscure movies and occasionally seeing an underdog win. If this was what people enjoyed most, then why not just do that? Three people are assigned a communal dictation of 2 films and discuss them and vote. If the overarching bracket structure doesn't bring enough to the table then it's just holding up the actual fun part of watching and discussing movies. If the long form competition does add something people enjoy then it should be respected and followed through on. If the concern is simply that the usual suspects win then take the usual suspects out of the competition, pantheon films need not apply. Again, I didn't participate in the brackets so I can't speak for what would be the right solution. I can only say that while I would consider participating in any of the above variations, my interest in a full bracket would wane if the whole thing took ages to complete.
I think fundamentally I just like to know where things are headed. I can deal with more structure or less structure, I have my preferences but I'm flexible as far as which path to take. But once a path is chosen I want to see it through (or, if necessary, decisively changed if it turns out to have been the wrong decision), otherwise why bother choosing a path in the first place.