I read this article too and while I don't like their advice (razor blade instead of a knife? c'mon!) you have to take it in context. They're talking about 'ultralight' hiking. Ultralight hiking is a fairly extreme form of hiking that many people don't really understand.

This breed of hiker is also the type who will spend an extra several hundred dollars on a single piece of equipment because it weigh 2 oz. less than what's cheap. They are also known for restitching clothing and gear to make it weigh less. I've seen modified ultralight packs weigh as little as just a few oz. where padding is removed and spare clothing is stuffed into waistbands and shoulder straps to help cut weight.

These people are also hiking on extremely well marked trails and are typically very familiar with the trail in question. Not everybody is ready to take on the 2175 mils of the Appalachian trail but these are the people who do it. I don't recall if it's mentioned but these trails are often well populated, in parks where there are rangers around all the time, and even have shelters and hostels along the way at regular intervals (The Appalachian has over 250 shelters peppered along it's length...doesn't seem to dumb to leave the tent at home considering that fact.

That being said, I don't like the way the article gives the feel that any average Joe can use these techniques to cut weight...I think that they're putting some people at risk by not being more clear about the sport...perhaps they're just assuming their readership are familiar with every aspect of backpacking.