Hiking for me isn't for exercise. When I'm exercising, I put 20# pound plates in a rucksack and walk the neighborhood. When I'm hiking (like the 1000 miles I did last year) I'm out there to enjoy nature and have an adventure, not be miserable every night with cramping feet.

Not only that, but there's plenty of evidence that extra weight brings a greater chance of injury when hiking every day. Being able to do 1000 miles over 3 months means you have be able to perform consistently and without injuries building up.