people spend lots of money on things that most others think are realy silly, like super fast cars, paintings, custom jello filled hot tubs. Most people I know think that over a thousand dollars for any bike is goofy. SO if someone had the splash to get a uber light wonder bike and pack half a toothbrush and three square feet of tyveck as camping gear, and the desire to do it, there is no knocking that. Or to pay to have a fully loaded tourer custom made to weigh ten to fifteen pounds. Even if you just want to go SUL on a off the shelf madone, if thats more in reach then no one can say don't(exept for your touring partner who is sick of letting you use everything they are lugging on thier 28 pound naked bike)

I go light bordering on ultra light sometimes. You can feel the difference, its fun. But its on a steel frame rig with enough spokes to handle a couple breaking.
Once I came on a road that had slid off the mountain. The workers told me that as it was two miles and traffic was going 25 over a rocky temporary road, they would drive me over it. The guys tossed my rig into the truck before I could get there to do it myself, on a bunch of tools, rocks, and barrier materials. It was nice to have just some scraped paint instead of the constant worry about damage to any carbon.