I have to agree with you — even if I am positively an anti-gun italian non-activist.

There’s a little problem in the fact that those video promote the ownership of guns, and makes them socially acceptable, which could be stated as one of the reasons shootings happen.

In most of the US gun ownership is socially acceptable and even celebrated. I think that's a good thing. If it were socially unacceptable we would have fewer people/representatives who were willing to stand up and support our gun rights publicly.