I'd rather spend 4 hours on a game that was perfect, the story completed itself to just the right level (doesn't need to tie every end but be full though out and if they go off into the sunset after dealing with the problem and finding out more about what it was, thats great better then a story filled with gaps all the way though and ending is abrupt and unsatifying). If the 4 hours spent wasn't filled with restarts to get though it, 4 hours of solid entertainment is a good deal better then 100's of frustrating and unsatisfingly shallow gameplay. I've said it before and say it again, Bastion hands down was the best game of this year, it was short, done in a day maybe two, I feel no need to replay it but it was just such an unbelievably pleasant experience I feel satisfied, if anything that a far better mark of a good game then one you just "kill time" in.
Just because some block puzzle falling game can whittle away the hours doesn't make it better then a gripping story that leaves you satisfied, thats how they work they don't ever satisfy you, it'll always be a higher score or better player to beat, like how many films and games won't finish now to get you to buy the next one, they'll rarely move forward in DLC and sometimes you won't even see the overarcing story move foward in the next part at all.

I was absolutely bored with the Thieves' Guild jobs, to the point where it took me almost a week to complete them. But I still did them because I wanted to finish off that faction. People will definitely keep playing a game after they're bored of it.

THIS!
Some games have a pathetic 10 hour linear single-player campaign.