Here's why:

* Strike-Slip Faults: These faults involve horizontal movement of rock masses sliding past each other. The movement is primarily lateral, not vertical. While they can create significant changes in the landscape, they generally don't result in the uplift and folding that creates mountains.

* Reverse Faults: These faults involve compression, where one block of rock is pushed up and over another. This vertical movement is the primary mechanism for mountain formation.

* Normal Faults: These faults are caused by tension, pulling rocks apart. While they can lead to valleys and depressions, they are not as effective in creating mountains as reverse faults.

Examples:

* San Andreas Fault (Strike-Slip): This fault is famous for earthquakes, but it doesn't create towering mountains. It causes lateral displacement, creating valleys and offsets.

* Himalayan Mountains (Reverse Faults): The Himalayas are a prime example of how compression and reverse faulting create massive mountain ranges.

* Basin and Range Province (Normal Faults): This region in the Western US features mountains and valleys formed by normal faulting, but the mountains are typically lower and less prominent than those formed by reverse faults.