It sounds like they are doing good work. I've used blankets and sheets as batting--mine had been well-washed (read old!
), so I knew they wouldn't go wonky, plus that way I put them to good use, even if they weren't "pretty" anymore. I knew a lady who used nothing but double knit in quilts--hand pieced and handquilted. She saw it as a wonder fabric--lasts forever, washes well, very warm, etc. Growing up and during most of her adulthood, all she had was worn clothing and muslin to use--double knit, to her, was magic! We need to recognize sometimes that our comfort zones-our "right" way to do things, can be limiting. I don't plan to make a double knit quilt, but I can now admire hers.