There is something almost therapeutic about finishing a game. Another accomplishment, another disc to put back on the shelf (metaphorically if you are not obsessed with collecting slowly decaying physical media), and the freedom to move on to another game without the slightest twinge of guilt, regret, or sense of failure.
Completing games has been enshrined in the culture by sites like Backloggery and How Long to Beat. I have a 6 year old spreadsheet I use to track what I finish and know other people who do the same. Gaming forums have threads on backlogs frequently; many of us feel the weight of our unfinished games.
Why do we want to finish games, and should we?… 2 h4rdc0r3 4 U.