Stylish, clued-up men are looking beyond Patagonia and going gaga for a new wave of hiking-style clothes. They’re good-looking—and, often, pricey. Call it Gorpcore 2.0.

It’s classic and timeless, and it’s super easy for me to sit and judge from the comfort of my hoodie that I’ve been wearing for multiple days. But since we’re all hoping not to see a single boring ...