Here's why:

* Lack of liquid water: Sedimentary rocks form from the accumulation and cementation of sediments. This process requires the presence of liquid water to transport and deposit the sediments. The Moon lacks a significant amount of liquid water on its surface, making the formation of sedimentary rocks impossible.

* Absence of an atmosphere: The Moon also lacks a substantial atmosphere. This means there's no wind or erosion to break down rocks into sediments, further preventing the formation of sedimentary rocks.

* Dominant geological processes: The Moon's surface is primarily shaped by volcanic activity, impact cratering, and tectonic forces. These processes create igneous and metamorphic rocks, not sedimentary rocks.

While there might be some trace amounts of sediment-like materials on the Moon, such as dust and regolith, these are not classified as sedimentary rocks.