Nylon is the most popular shell material for snow pants for good reason — it's tough, abrasion-resistant, and handles the wear and tear of riding really well. Whether you're skiing groomers, hiking for fresh tracks, or sitting on cold chairlifts, nylon holds up to the abuse better than most alternatives.
One thing to pay attention to is the denier (D) rating, which tells you how thick and durable the fabric is. Higher denier means tougher fabric that resists snags and tears, but it also adds weight. A 70D pant is plenty for most resort skiing, while 150D or higher is great if you're hard on your gear or ride a lot of trees and rocks.
Nylon is a solid all-around choice for most riders. It's not as stretchy as softshell options or as premium as Gore-Tex, but it strikes a great balance of durability, weather protection, and price. For most people hitting the mountain regularly, nylon gets the job done without overcomplicating things.