there are so many variables that come in to play whether or not a quilt will last- i made one back in 1976 that to me is (aweful!) but it is still used and loved- and i have never had to do any repair work on it- i've made quilts that only a few weeks later looked as if they were 100 years old and abused...falling apart- faded, frayed---not even saveable
and i can hear you saying---well the fabrics were different back in the 70's- but i think it's the choice we make-regardless- i've used vintage fabrics that have disintergrated- i've used newer fabrics that hold up for years-the batting is a factor- how it is laundered- and how often- how it is stored- even location (is it a humid enviroment- or a very dry one?) does it get alot of sun?---lives on a bed in a light/airy room? is it stored in a cedar chest- or in a closet? so many factors- i would not be comfortable to just blame new fabric quality---there may not have been as many to choose from 50+years ago---but there was still a vast range of quality---just like today-the statement is just to (general) i bet there will be many many quilts made today still around in 100 years