The folklore that i was raised upon said this. The Clubman bars were developed by the British guys who would ride during the week, and race in their club races on the weekend. Back in those days, the only controls were a clutch lever, a British button for the horn, a throttle, a "dipswitch" for the light. And a grip to swap.
So after riding all week with the bars up and comfy, they would show up at the track (trailers were for sissies) flip their bars over in a matter of minutes, and go racing.
Happy if anyone tells me I'm all wet. But a simple and elegant story.
Which would mean anyone giving you grief for having them in the Up position doesn't understand the background.
And if both positions are utilitarian, which is the right way and which is upside down? I submit there is no right or wrong, just up and down.