Here's why:

* The Sun is the central and most massive object in our system. It exerts a gravitational pull that holds all the planets, moons, asteroids, and other objects in orbit around it.

* The Sun provides the energy that drives life on Earth. Its light and heat are essential for plants to grow and for all life to thrive.

* The Sun is the most prominent and important object in our system. It is the reason why we have a system in the first place!

Therefore, it makes sense that the entire system is named after the dominant and vital celestial body at its heart - Sol, the Sun.