i agree with some of the points about high costs (e.g. cuben shelter), but in lots of ways the UL movement is about LOW costs, instead of high. carrying and using less stuff, buying simpler items with fewer features made by cottage manufacturers. i know that my golite ion is lots cheaper than my old $400 backpack! and a silnylon tarp is too. the SUL/UL movement is a funny combination of simple gear + not much gear + super high-tech materials/gear. this equation means there's room for obsessiveness in a few directions (i.e. monastically doing without, buying the craszy-expensive newest and lightest, being cold and going hungry, etc.)
i think there is some feature creep here and there, but in lots of cases i'd welcome it. for example, i find the Golite Ion a bit lacking (i.e. that's why i added a bungee system like lots of other people), but i think i'll find my new MLD pack EXACTLY on point (with roll top, side water bottle pockets, bungee system). it's not much more weight, but MUCH more useful. so maybe it's "right-sizing" in some cases - just taking that reasonable step up from complete barebones to a minimal feature set that WORKS.
let's remember, BPL people mostly ARE the lunatic fringe, those who WANT to be the lunatic fringe, or folks who want to LEARN from the lunatic fringe. it's not normal backpacking folks!