When learning to ride, my dad taught me to always have the inside pedal up when cornering. He reinforced the lesson by telling me about a race he'd been in where someone clipped a pedal when cornering and took down 20-30 people in the pack behind him as he went down.
To me it's quite intuitive to keep that inside pedal up - it keeps it away from the ground when leaning into a corner and I'll often even hang my knee on the inside as I'm leaning to lower the center of gravity even further. Additionally, I think that I'm actually pushing on the outside pedal as I go around, which also feels very natural to do.
The vast majority of people I see riding these days (recreationally or light competitive, not professionally), including (much to my chagrin) my own children, insist on putting the inside pedal down when turning. I suppose that there is a belief that "my foot is closer to the ground, so if I start to crash I can save myself more quickly", but it just seems so totally counter intuitive and unnatural to me. It feels very unbalanced to have that inside leg down, like I'm going to fall over on it.
Why does this feel like the "right" way of going around a corner to so many people?