Here's why:

* Composition: The asteroid belt is primarily composed of rocky and metallic objects. These are remnants from the early solar system that never coalesced into a planet.

* Distance from the Sun: The asteroid belt lies between Mars and Jupiter, a region too far from the Sun for ices to remain stable.

* Gas Giants: Gas giants, like Jupiter, Saturn, Uranus, and Neptune, form much further out in the solar system where ices are abundant and can act as building blocks.

While there are some icy bodies in the asteroid belt, they are relatively rare. The majority of the objects are rocky and metallic, making the belt a rocky region overall.