A positive thing about toy guns would be learning some gun safety - like not pointing them, etc. They can also learn some history by playing cowboy, pioneer and the like. Guns are a reality and they are not necessarily violent toys. All three of my kids had toy guns (I think) and they were just...toys.

Now that my kids are adults, two of them still enjoy target practice and are very, very good with guns. One son is a good hunter. Kids play with cars and "wreck" the cars....but that does not lead to driving into buildings and intentionally into other vehicles to make a crash? I believe that pretending and using toys is a healthy thing. Parents need to supervise smaller children and can use the toys to do this. For example - talking about safety and history the same as they might explain caring for a babydoll - see what I mean?

Plastic or metal toy swords, guns, cars, etc - they are toys and provide fun and learning, make-believe, etc.

Hope this is a bit helpful - is my opinion.