I don't like all the chemicals and pesticides on my hands when I am working with fabrics. I don't use spray starch, either, for the same reason. I just like the plain clean cotton.
But I do professional dressmaking, too, and I have a churchful of young ladies who depend on me to sew and alter their special dresses. (It's usually my wedding gift to them - to do their sewing for the wedding.) I don't prewash those fabrics, or other specialty fabrics that are not machine washable. Instead I hang them in a well-aired place to release fumes and dust/lint until I am ready to cut and sew. I wash my hands often while I am working with them, too.
If the care instructions are to cold wash and hang to dry, I will do that. I hang most of our clothes to dry, anyhow, and mostly just use the dryer for prewashing fabrics and battings.