“They also breathed air.....Ban Air!”
I would agree with you if we’ve had ~20 year old boys breathing air for thousands of years and have had them being mass killers for just as long - but we haven’t.
But in the case of violent video games, there CLEARLY is a correlation between the increasing popularity and ‘quality’ of those games and the increasing mass killings by those boys.
Whether it is the CAUSE, or even a factor, can be debated, but the correlation is there, whether parents want to deal with it or not.
It’s a symptom of the disease.