Because she really does not know what she wants. And it's not up to you to decide that. Believe me, I have thrown that and variants of "Why are you doing <stuff>? I still throw out that question. It's less frequent, and it may have gotten to the point where I don't really care. That's her BS to deal with.
Sums it up perfectly right there but I think part of that is what makes what we go through so hard. It is painful for me to see someone I love so much so lost and confused. But I hear you, at this point it is up to her to deal with how she sees fit. I'm sticking with the you made your bed now lie in it mentality.