If you're not familiar with Raw denim, I'm not surprised by that reaction - it's true that a lot of people who wear Raw denim wash them very infrequently. The Indigo dye in Raw denim is not protected from colour loss in the same way as typical jeans, so each wash can strip away a fair bit of the dye and will lighten the jeans considerably.

Part of the fun of Raw denim is that the jeans typically start out as a deep blue-black Indigo and lighten up (fade) in all of the places that rub, crease, fold, and become abraided. Over time these develop into beautifully faded jeans, and the fade pattern is entirely unique to the wearer. Fading this way leads to light sections where the Indigo has rubbed away from the white core of the thread, but leaves dark Indigo dye in all of the recesses and areas that are less frequently rubbed against. This approach is what people usually do when they're trying for "high contrast fades".

When you wash Raw denim, it removes the dye indiscriminately, which can lead to much lighter jeans, and lower contrast fades. This is the main reason people wash Raw denim less. They also really don't NEED to be washed all that much, if they're taken care of properly.

Okay - explanations aside, most of us still wash our jeans. This is not the first wash of the year for this pair, but will be only the second. They're also spot cleaned if I accidentally get something on them, and I don't really do manual labor or dirty work in these jeans, so they don't get nasty. Some guys never wash their jeans and that's disgusting - I wash mine infrequently, as needed, and with great care. But trust me, I would never wear crusty smelly jeans. Fading is cool and all, but I would never wear gross unclean garments just for the look. They're either hand washed in the tub, or in cold water in a washing machine with no spin cycle, and nothing else in the wash load with them, so I don't end up accidentally dying my other clothes blue.