That fact that most manufacturers sell most guns in the USA. The government controls what guns are legal. In order for these companies to make money they need to create guns they can sell. If you can’t buy the gun here, they won’t sell many. It is simple business. I’d imagine Colt isn’t going to sell very many $800 plastic pistols over seas to terrorists, when they can just go buy a AK-47 for $47 and a donkey.
Exp: Why don’t more companies sell cars without airbags to make them cheaper and lighter? They can’t…
I could however see china making a cheap plastic gun in the future. They are the new Russia to me.
Edit: You guys beat me to it. Its all about the $$$.
But in theory it can be done.