>>44043865>>44043880>>44044282Dark type isn't about literal darkness, it's Evil type in Japan, that's why a lot Dark moves are based on dirty fighting tactics. Foul Play, Sucker Punch, Feint Attack (Sneak Attack in Japan). Dark Pulse isn't pulsing darkness, it's about dark (evil/violent) thoughts (it's called Evil Pulse in Japan).
So no, Light being good against Dark type doesn't make sense. Fighting in good against Dark because martial arts can help you protect yourself from attackers. Fairy is good against Dark because Fairy is supposed to be a wondrous magical typing that's pure of heart, don't ask me why Ghost is to Dark, probably has to do with a lot of malevolent ghosts haunting where they were (and haunting because they were) murdered.