I find that statement weird, considering Fallout didn't have that many memorable characters (at least not more than several other CRPGs out there), and it really wasn't one of the game's strong points. Most characters people remember are either the ones they disliked because of bad AI (Ian shooting players in the back, Dogmeat getting stranded in map corners) or those with animated faces and forced quirkiness (Harold, Sulik, Marcus).
The key difference between TES (Morrowind, specifically) and Fallout, in regards to characters, is that characters in Fallout, wheter major or smalltime don't feel lifeless.