Some of the more elderly shooters find they can no longer "focus" on a standard rear sight due to aging eyes. A peep can eleviate the problem.
The rationale behind the ban, for 40 years that the flint season existed, was to limit the flint guns to pre-1800 style traditional flintlocks. That original concept has been vastly eroded by gradual step by step giving way to more dmodern concepts. Originally, the guns had to fire round balls. That limitation was removed about 20 years ago. About 2008, the words originally permitted "open sights only" That prohibition against peep sights was removed with great fan fare as a "help" to aging hunters. Then about 2011, the Commission amended part of the law and for some inexplicable reason (probably due to a staff lawyer's screw up, the phrase "open sights only" was put back into the regulation. Then we had the ridiculous situation that the regulations prohibited peep sights but the Commission still advised mistakenly that peep sights were legal. When asked about it, one of the staff lawyers replied that "open sights are peep sights" Well for the prior 40 years peep sights were officially NOT open sights. I suspect it was a case of a staff lawyer providing language for a regulation when he knew nothing about the subject.
Anyway, the commission recently changed the language to permit peep sights again.
As another example of not knowing what they are doing, the commission for years (byt not in wirting) considered cap and ball revolvers as muzzle loaders, yet the regulation definition expressly said they were not. Then their position changed, to them being neither muzzle loader, rim fire or centerfire, which made them illegal for hunting, A few weeks later, they indicated that cap and ball revolvers were center fire for purposes of the hunting law. A recent change to the definition of muzzle loader now includes a breech loader that uses loose powder and ball. But cap and ball revolvers are not breech loaders either. So I guess they are still centerfire. I keep an old remington cap box that is labeled "Center fire" just as proof that my cap and ball revolvers will be legal the same as any centerfire pistol.