I've seen quilts made from thrifted wool clothing -- our church ladies used to make them. The advent of polyester pants suits put an end to that, as they apparently much preferred working with the bright colors and patterns of polyester pantsuit remnants.
I remember one that used buttons taken from the garments at the center of each block to tack the pieced top to the backing -- clever use of the whole suit.
I do think that they would be better to tie or tack than to try to do much quilting. They're very heavy, for one thing, and the thickness would be hard to navigate on a domestic sewing machine.