huh. freeform PnP is a nice idea but it rarely works out that way. the standard division of labour in PnP (the DM creates the world and the adventure, the players create the characters) means that there's typically very little use made of the PCs' backstories: the quality of the backstories varies wildly (e.g. farmboy with lust for adventure, parents killed by orcs, etc); and DMs prefer to push the story they have written.
conversely, where DMs do get involved in working PCs backstories into the campaign, then they tend to railroad players every bit as much as CRPGs do ("you can be anything as you like in this campaign, so long as it's either a human from the great kingdom named Thargos, a half-elven assassin from hyborea, or a gnome illusionist from the secret gnome city.")
let's face it - most PnP sessions don't actually involve that much roleplay anyway.