greatbasin

When you're hiking over 2000 miles and from March through September at elevations ranging from 0 to 14,000+ feet, you will run into all kinds of weather, temperatures and conditions. Thru hikers can also hike through the winter, but it's fair to say that many of the extreme routes are attempted in the best weather possible because they would simply be impossible otherwise. With respect to weight, those thru hikers that are carrying 20 to 40 pounds or so are definitely dealing with sub-zero temperatures (-18 deg. C), high winds in the mountains at over 10K feet, and with rain and snow. A thru-hiker with an ambitious route seeks to avoid extreme weather -- they're typically going to prioritize mileage and route completion versus some kind of storm chaser -- nevertheless, they have to be prepared to deal with anything.

Taking a zero-degree rated sleeping bag versus a 30 degree rated bag doesn't add a ton of weight (especially if you're willing to pay $$). Nor does taking rain gear. Thermal underwear and some insulation to wear under a shell doesn't add many pounds and is often enough when you're on the move -- it's cold sitting around in camp, so you just get in your bag earlier. There is definitely a trade-off between being lightweight and being comfortable in bad weather, or being lightweight and having all the varieties of food you like, or being lightweight and having non-essentials you appreciate -- like books, watercolors, additional camera lenses, or a 'walkstool.'

Just like bicycling itself, it's fair to say that in backpacking or other self-contained travel like cycle-touring, there is a trade-off between lightweight and cost. Going light is mostly a matter of choices about what not to take. Those last few pounds and ounces can sometimes be about exotic materials and more expensive versions of the same thing, but costly gear won't transform a 60 pound load into 30 pounds, the same way it won't transform a 30 pound touring bike into a 15 pound road bike -- the transformation isn't just cost and material choices. The 15 pound road bike flat out omits many of the features, benefits and capabilities of the tourer. The same is true for cargo. If you want to scramble some fresh eggs on a griddle for breakfast, you can't cut that weight in half by getting a titanium griddle and carbon-fiber eggs. You simply need to forgo.

Bikes, especially on flat routes and with the proper racks and bags to hold it, do enable a great deal more weight to be accommodated. I have no criticism of the OP's 60 pounds. I'm only responding that it can be done with less, a lot less. It's up to each traveler to evaluate their cargo and decide what they're willing to lug and look into alternatives when they want to take less.