I agree with everything you wrote, except the bolded part. It wasn't too long in the past that open carry was reasonable and practical under certain circumstances. Farmers, ranchers, hikers, fishermen, people who lived in rural areas where a gun was a tool for more than repelling humans, etc. Outdoor activities lend themselves well to open carry. Back when this was a commonly accepted practice, it was the people carrying concealed that were considered gangsters and thugs. I think having a law against open carry is not taking these things into consideration.
Hence the number of states that allow open carry yet no concealed carry.