Different genetics: all these complex hybrid Phalaenopsis have a lot of different species in the mix. I grow a bunch side by side and have a real mix of leaf conformations. In the grocery store it could also be water stress: a lot of times the flowers will still look good even if the leaves are drooping from dehydration.
The light direction and gravity will also affect leaf direction. I'm short on growing space and will re-arrange my plants depending on what's blooming, etc... Sometimes this leads to weird growths but I'm not trying to win award shows. I usually try not to disturb a plant when it's in spike as that can make weird flower growths.