And when it was written militaries where standing in lines firing round shot out of inaccurate tubes en-masse hoping that they might hit something. A single person with a modern SAW could have taken out an entire company unaided. You're suggesting that there should be no adjustment based on changes to society and technology because it's written on a specific piece of paper.
Grapeshot. Pickleguns. There were many advancements in weaponry during the lives of the founding fathers but I don't remember them writing all about how they were wrong because weapons are too dangerous for mere mortal civilians to own.