The only commonality between hiking 10,000 years ago, and now, is that you actually walk from one point to another. Everything else is a compromise (gear, modern clothing, how you obtain food, what kind of food, how you cook your food, how you navigate, etc.). Who’s to say that one compromise is less acceptable than any other. I seriously doubt that someone that chooses to slackpack will regret that decision one bit, and could care less what others think.
For some, slacking is the only way they can do long distances. I think of Attilla the Hun, a small, sickly older man who completed his thru hike in 2007. We were doing Maine, south to north, and we ran into him three different times as he hiked south to his next ride north. Spent the night with him in the strange, abandoned Ski Lodge near Stratton, then met him at Gulf Haggus. He was elderly and had bad health conditions (I was there one night when he took all his pills). But he was able to do the trail only by slacking with the help of drivers. In some ways he put out a lot more effort, at higher risk, than younger, healthier backpackers.
my chosen method of hiking is to section-slackpack. Is that easier than thru hiking? Of course it is, by a significant amount. But then again I didn't start until I was in my late 50's, and if I'm fortunate enough to complete the trail (halfway at age 60) it'll end up costing north of $50k. I don't see it as missing out on the full AT experience. I've stayed at enough shelters & slept adjacent to enough stanky snorers to not feel deprived. I believe the experience of staying in trail towns provides a much richer experience. And lets face it - most thruhikers spend a fair number of nights off the trail, maybe a 90-10 split or thereabouts. My ratio is reversed. I can no longer throw the vigor of youth at the AT, so I don't consider it "cutting corner." If someone 40 years my junior wants to consider it that way, well, get the heck off my lawn!
I've done zero slackpacking in 1,550 AT miles but I have a feeling that may change when I make it into the Whites in a couple years.
It's all good in the woods.
Just do what you want, call it what you want, hike your own hike. Just don’t lie about it!
The Five Basic Principles of Going Lighter ~ Cam "Swami" Honan of OZ