Historically, Dracula's name mean's "Son of the Dragon". His father would be the first "dragon". Maybe he had daddy issues feared his dad, so that's why there is that dragon restriction on the card. Or maybe since he's a "dragon" it has some kind of Beetlejuice effect (google it).
And since he was a mass murderer, name is used in a negative connotation, that being demon/devil/evil/etc, so it would make sense that you wouldn't get the EXP from angel-types since they're two opposing forces.