Yeah, some classes are definitely more restrictive than others. But even in that situation, look at the antagonist in Siege of Dragonspear ... would her dialog and story have changed significantly if she were a warlock or paladin? Would the Irenicus story fall apart if he were a fallen ranger instead of a sorceror? The class selection gives the character a set of tools with which to overcome obstacles ... this guy has a hammer, she has a wand, etc., but the character's story arc *could* be based on so many other interesting things.