Those that do not sew or craft do not realise the time involved. That means buying the fabrics - and we all know how much time that takes to match fabrics - the pre-washing, ironing, cutting, sewing blocks, placing blocks and moving them around to get it just "right" and sewing them together, sandwiching, pinning/basting, quilting and binding.
They only think of the sewing part hence to ignorance.