Here's why:

* Ocean mountain ranges are formed by plate tectonics at mid-ocean ridges, where new oceanic crust is created. This process can create vast underwater mountain ranges, like the Mid-Atlantic Ridge, which is the longest mountain range on Earth, stretching over 40,000 miles.

* Continental mountain ranges are formed by the collision of tectonic plates, causing the Earth's crust to buckle and fold. While these ranges can be impressive in height (like the Himalayas), they are typically much shorter in length than their oceanic counterparts.