Yeah, it's a fair question and it's actually very hard for me to find the root of it. On one hand I do believe we'll be married forever, but on the other hand it would feel very strange to send a huge amount of money to my wife for no reason.

Maybe it's that our earning has been so separate that it "feels" like it belongs to an individual vs a unit, in the same way if we order at dinner it would be weird if I just started eating her food.

I've really been thinking a lot about this since you left your comment and I feel like it's one of very few things where I can't come up with a good answer, even to myself. My aversion to it seems to come from enjoying managing money without feeling like I'm risking someone else's money (my wife is a bit more conservative with her money) and spending without feeling like I'm making a decision for someone else. I think my wife feels the same from the conversations we've had on it.