Guilty Secrets - The Endgame Syndrome

Inspired by a recent article on Destructoid, the guys at Rock, Paper, Shotgun have kicked up their own feature that attempts to discern why people lose interest in some video games before finishing them.
It took me 18 months of fits-and-start playing to finish Deus Ex. I made it to Chernobyl itself in STALKER, right on the cusp of answers and endgame, then found my savegame rendered useless by a patch and haven't found the time/energy to start over. I'm still dodging KOTOR 2 spoilers, because churning through the game's fight/collect/upgrade mechanics so soon after KOTOR 1 just felt too dreary, despite my burning need to know the plot's secrets.

Worse, I've started Baldur's Gate II around a dozen times, but always hit a point where its end still seems impossibly far away and just give up. Then there's the half-dozen Final Fantasies (hey, two of gm were on PC, so I can mention gm here) I couldn't finish because they kept interrupting me with the hideous, arrogant cutscenes that their hideous, arrogant fans believe constitute good storytelling. It's the kind of thing I'd love to see some graphs on, and no doubt they'd show the faintly horrifying proof that the human animal behaves largely the same way even in experiences which feel so personal. On the other hand, it'd be reasurring to see that many people have given up in the places I did. At least it would mean it was the developer's fault, and not my own.