For reference, I thought of those points of the fly so perhaps you or others can think of positive and negative points too.

I agree with you, which is why I personally fold down the top half of my bedding.

As for design/looks I likely described this wrong. Bedding is designed to be made full on the bed. It's not a circular argument. The design is best when the bed is made as you can see whatever design is on the pillows, sheet, etc.

Another reason: it's a small accomplishment that could be a good motivator for your day (especially if you're depressed).