I remember, playing Nintendo games as a kid, that finishing 100% of a game wasn't important at all. All you had to do was beat the game.
Super Mario Brothers 3 (a great game, and still one of the best in the series) was the perfect example of this. In SMB3, the thing to do was find the three warp whistles and SKIP to the last board. If you really enjoyed a particular board, you might wait to use the whistles until after that, but eventually, everyone, sooner or later, warped ahead.
Then came Super Mario World for the SNES. Suddenly, many of the boards had two or three exits. I remember sitting on the floor with my handy player's guide trying to find every single one. I even spent time in the wacky gnarly boards and came out in the weird different colored world. You didn't get anything for doing all of this other than a sense of completion.
Now, developers hide rewards for getting 100%. How many of us spent hours tracking down every puppy and synthesis material to get the hidden ending in Kingdom Hearts, or spent frustrating hour after hour searching for that elusive figment in the race in Milla's brain in Psychonauts. And how many repeatedly tracked down and got trounced by Ultimate Weapon in FFVII to get the Cloud's Ultimate Weapon?
Why have we become so obsessed with getting 100%? My husband posited that since so many gamers are older now (ie, we were children playing the Nintendo games our parents bought us, now, we work for and buy our own games), we want to get our money's worth. A game may only take 10 hours to complete, but for $60, we want more than that. And so we keep playing, getting every last little bit we can out of it.
I'm not sure if that's the reason? What does everyone else think?