My mom took lessons from an old Preacher once upon a time, who due to infirmaries of age would ride side saddle....reportedly to church, throw his robe over, dirty boots sticking out the bottom, conduct service, then ride home.
It was not uncommon to see men riding aside after the Great War (WWI) There were a great many amputees. They would ride (and foxhunt) in near side or off side sidesaddles depending on which leg had been amputated.
For riders suffering from hip arthritis or other infirmities that compromise their ability to ride astride - sidesaddle may be just the ticket.
Brothers and sisters, I bid you beware
Of giving your heart to a dog to tear.