I hike relatively light by some standards and I have hiked relatively heavy in the past. I learned to lighten my pack long before I researched anything and it was done simply by learning as I went. I have seen heavy packs on many and only once thought about questioning their gear choices since it is their burden to carry. The one time I did question gear was last summer north of Newfound Gap when I passed a hiker on my way to Icewater Springs. I passed him less than a mile from the shelter and beat him there by almost two hours. He had a pack that must have weighed 10 lbs. on its own before the probably 80+ lbs. inside. Strapped to this pack he had a typical school backpack that carried his food since he had no room for it inside his main pack. When he got to the shelter in the rain, wearing only cotton clothing, he was miserably soaked and cold. There were three other hikers in the shelter that night who were all fairly light. I wanted to speak up, but I kept my mouth shut until he asked us about our gear. He was going to keep his hike (slated from Newfound Gap to Roan Mountain) going and just get to a store from Davenport Gap and change his outlook on hiking. He learned on his own and four lighter hikers did not give him grief over his gear choices but helped him a lot once he started asking questions. Some of his contents: three changes of clothes, 10 rolls of TP, food for at least 20 days (resupply never even crossed his mind), a military E-tool, a plastic salad bowl for washing, a complete Coleman mess kit, and too many more things to mention. His attitude was surprisingly great on hiking with his little education and miserable situation and he was happy that we did not make fun of him. I have no idea if he made it to Davenport Gap since I left early the next morning and went there that day and on to home.
We who have hiked for a long time often laugh at what we see carried by others. In this day and age of instant information from the interwebs we forget that not everyone reads the different sites that we frequent. Therefore, not everyone even thinks about going lighter since they take what they think they need. Some will be miserable and never hike again while others (me included) will evaluate their choices and lighten their loads with each and every hike. My first overnight hike I carried probably 50 lbs. with food and water. On my first long-distance hike I carried about 30 lbs. with food and water. By my third long-distance hike I had a base-weight of 12 lbs. When cold weather is certain I probably have about 15 lbs. now and during warm or hot weather I come in just under 10 lbs. (my cold-weather sleeping bag is nowhere near light and is 3 lbs. 10 oz. in addition to needing a compression sack and separate compression straps to fit into my pack). Going light is a personal choice and a state of mind. Many will do it on their own without ever consulting others while others will seek out information and analyze the sources of that information to determine whether it is a valid source. We will see these people on trails across the country in various states of "light" and by commenting on their loads we can either make them resistant or we can enlighten them. As with anything we do in life, hiking is personal. What works for me may never work for you and vice-versa.