the way I see it in my head two crossings means two exposures to traffic, two chances to be in a driving lane, why not split the difference and walk across diagonally.

Have you considered that walking diagonally exposes you to all four lines of traffic at the same time? I’d definitely feel less safe being in the middle of a diagonal crossing than crossing the street twice. As you mentioned, drivers also won’t expect you to be in the center of a crossing.

Honestly, it sounds to me like you think crossing the street in a more dangerous, unpredictable way is safer because it’s a little faster.