That's A Good Question

Someone asked me the other day, "Why WOULDN'T someone want a doula at their birth?"
I have a couple guesses, but honestly I don't know. I've even had women know I'm a doula, seem very interested in me attending, but eventually decide against having a doula.
Various reasearch studies show that women with doulas experience less pain, have fewer interventions, and are less likely to have a C-section.
However, doulas are still relatively new to the scene in America. Many women don't even know who they are, what they do, or how to find one.

So, I'm asking you--why wouldn't you want a doula at your birth?