Sounds like you two didn't get to know each other very well.
Or, when times were good you got off on splashing it all around and she came to think that would be normal.
Or, both.
Just for educational purposes, what would she say?
Or, maybe she never sees you because you're always working ans only come home too tired to do anything but want sex and she is so lonesome she could cry but because she doesn't know how to verbalize her feelings she sublimates it all by contolling at least ONE thing and that's spending money. ? (sort of like when people eat to feel better. It's a form of self love)
That's all I got right now.