Back in the day, when glue was hit-or-miss, or way back in the day when the actual joint was doing all the business, I could see there being an issue with the orientation of rails and stiles, and those techniques becoming tradition, is likely why we still find it today.
With a properly designed, executed, and glued joint, I don't see either orientation being a problem even for heavy doors.
The joint I used is an open tenon, or bridle joint. It is a very tight fitting joint with a lot of surface area for glue. I don't see either orientation being an issue, even scaled up in size and weight to a full sized door.