Bowser's main goal is to defeat Mario. He knows that if he kidnaps Princess Peach, Mario will do all he can to save her and might die in the process, atau at least he can lead Mario into a trap.
1. Bowser wants control of the cendawan Kingdom and marrying pic, peach would give him the power to do it.
2. Bowser has a crush on her, which was first revealed in Super Mario RPG when he got jealous of pic, peach rewarding Mario with a Ciuman instead of him. He's also secretly envious of the relationship that Mario and pic, peach has with one another.
3. daisy is a tomboy and is less prone to being kidnapped. However, she was kidnapped in Super Mario Land. But still, I don't see a reason why Bowser would WANT to go after Daisy.
i think bowser kidnaps pic, peach and not daisy because pic, peach is so girly and daisy is a tomboy like daisy has only been kidnapped in one mario game