this is what happens in a lot of places, with regard to movie and TV/broadcasting regulation in a lot of places, however it doesn’t happen as quickly as we would like.
In fact, this reminds me of something that happened in the UK in 2003, relating to the original Spiderman movie. The movie caused an uproar in the UK because it was rated as a 12. Of course, because it was Spiderman a lot of kids younger than 12 wanted to see it and their parents were happy to let them. The age classification caused such an uproar that the rules for age classification had to be changed and the changes led to the introduction of the 12A age certificate (I should probably link to my earlier post about UK age classifications shouldn’t I)