For me it is the cost , I infuse OO with chamomile and use that in castile soap. I love the smell of it infusing in the oil. I think the infusion adds a wee tiny bit of scent to the soap , but not much.
I use chamomile in my facial toners along with calendula extract and peppermint eo. I also use it in a couple of different soap recipies like my GENTLE CHAMOMILE face and body bar mmmmmmmm!