I used to always stand up to wipe. At one point in my adult life, there was a conversation and I realized everyone else does not do this. Then I tried wiping while sitting down. So much easier.
There are three main parameters: stand/sit, front-to-back/back-to-front, front-access/reverse-access (i.e. between the legs or behind the back)
Back-to-front is a health risk for 50% of us, and just a bit gross for the rest. So rule that out.
Wiping hand between the legs is awkward and requires that the thumb (a notoriously larger-than-the-other-digits digit) is used as the primary wiping vane.
Sit + wiping hand behind the back + wipe front to back allows use of the index finger, but requires an awkward lean and lift of one cheek to gain access.
Stand + wiping hand behind the back + wipe front to back is, therefore, the only sensible option. Additionally it makes checking the bowlean return value indicated on the paper much easier.
I think this starts because as a kid maybe it is easier to stand up? And no-one ever told you to stop because once you are old enough to handle your business on your own no-one is there to see and offer advice.
