It's because Bioshock gives you far more choice in terms of play style and customization than just about any other shooter I've ever played. There are TONS of Plasmids and tonics that you can use to alter your character and thus your play style. Want to be a good hacker? Choose tonics that slow down the process or eliminate some of the obstacles. Want to focus on melee combat? Equip tonics that make physical damage hurt less and tonics that make your physical attacks do more damage.
It's all about choices and how you want to play the game. Regardless, if you don't like first person shooters, there's no point in playing it. It would be like playing a racing game for the car customization.