While ESRB ratings and other warnings about violent games for kids have good reason to exist, many parents still ignore them, aren't aware to them, or simply don't care about their warnings
"Many parents still ignore them", which is fine, they are warnings not commandments.
"or simply don't care about their warnings", which is fine, they are warnings not commandments.
"aren't aware to them", which is a publicity issue for the ESRB and not the fault of the parents -- assuming for a moment that anything more than a statistically insignificant number of people aren't aware of them.
The ESRB warning are there so that parents can make decisions about their own children themselves. That their decisions differ from yours isn't a failing of the warnings. It's a failure of you for wanting to control other people's lives.