That is my experience and observation as well. Most ultralighters have no back up plan if something goes wrong. I've seen a number of them shake down their packs:

-no medical, or a business card piece of molskin and a couple feet of duct tape
-no firestarter, or a book of paper matches with half the matches and most of the jacket torn off to save weight
-less than liter of water
-no water purification, FOLLOWING A RIVER WITH BEAVER DAMS EVERY MILE (yes, I know I'm shouting- it is frustration)
-no whistle, no mirror
-no rain gear, or they cut down their ponchos to the point their legs weren't covered
-wearing shorts, nylon socks and tevas (in October in the Green and White Mountains)
-everything is made out of ultralight material that can't take going off the trail- I watched on pack literally come apart as the user tried cut through a rasberry thicket

They are fine if everything goes according to plan. If it doesn't, and they can't hike out to a town where their cut down credit card is accepted, they are in deep something. I've got no problem with lightening the load, so long as you don't eject your common sense in the process. Reading various websites and forums and listening to conversations at outdoors shops, it seems like too many of these guys are in a race to see who can furthest with the lightest and win the title of the baddest dude on the trail.
I take a lot of tips from them, but you won't see me using a pack that is made of material so thin it is translucent or failing to have the means to execute Plan B.