The native Scots will tell you that it's "just not done" in Scotland today. Nobody wears horse hair sporrans except the military and pipers. That seems to be the situation with modern Highland traditionalism.

However, I have seen at least one Scotsman wearing one. He was an official at a Highland Games in Scotland. So it would be very rare and likely frowned upon in typical dour Scottish disapproval, but it's not unheard of.

As mentioned, hair sporrans have a very rich history for civilian wear, dating back to the Victorian era, and seemed to die out during the Edwardian era. There are folks who would like to revive this tradition, including me! It's not an everyday sporran, though. I mainly wear mine with evening dress, although I'd certainly consider wearing it for very dressy daywear, under the right circumstances.