You are missing the understanding that the laws are not necessarily logical particularly without insight to the time and place.I'm obviously missing something.
In all likelihood the laws were passed with the intention of restricting the season to traditional single shot iron sighted firearms. The issue arises as most hunters seem to see it as a way to extend the season and nothing more. However people are clever and it did not take long before we come up with scoped up in lines. Just look at how archery has changed over the last century to see how we can alter the traditional to suite our whims.
From another perspective the mainstream firearms industry has taken the Muzzle Loader season as a green light to develop another market for the latest greatest. Thankfully we do not have to abide by the mainstream firearms industries bidding.