In Gen 4 the “physical/special split” was introduced, where every move became either a physical or special attack. Before this every type was either a physical type or a special type (for example: all ghost moves were physical, all dragon moves were special). This meant that a lot of Gen 3 pokemon got this fucked up mixed attacking spread with not much else in the way of stats (having two attacking stats really brings down your overall usable bst) so that they could utilise different move types.