Part of the reason I love Mearls:
my job as a GM is to chase the characters up a tree and let them figure out a way to get down. The thing is, there's a snake climbing the tree, the tree's on fire, there's a mob of zombies around the tree, and the rescue chopper floating overhead is piloted by a drunk 5 year old. You've got choices, but none of them are "I sit in the tree and while away a pleasant afternoon with happy thoughts." There's peril in every direction. As Ralph said in the quoted bits above, not choosing is still a choice with interesting consequences.
Most D&D players want a background that looks like this:
1. My character has no notable friends and family.
2. My character didn't have any major villains or real issues with anyone.
3. My character wants to... get some treasure?
Since I'm all game theory and linking other people's stuff today, here's some more stuff that chased down from someone else linked from mearl's LJ. Mostly for my own reference, but feel free to enjoy it as well:
Great set of five articles about gaming: character motivation, central conflict, etc.