I read somewhere that it has to do with kids that went through puberty or have not gone through it yet. At the peewee level its a pretty big jump between a 111/12 year old and a 13 year old.
Kids necks are not developed enough before puberty to be able to support the head during an impact.
Look at Pop Warner football - Numbers are way down because parents do not want to risk there kids long term health.
Another issue is there is no baseline testing so whenever a kid gets rocked - goes to Dr - Dr will always say its a concussion to be on the safe side.
This past year in peewees my kid ran into another kid head on. My kid was not right for 3 weeks. Constant headaches, sensitive to bright light. It was a real eye opener as to how much an effect this had on him.
Yes hitting is eventually going to happen. Not really sure what the right answer is and there might not even be one.
The other issue is that the long term effects of hitting usually come way after your kid is done playing so its hard to correlate the cause.
If your kid recovered completely in three weeks you should consider him and yourself lucky. I know kids that lost 2+months.
A lot of parents are casual on this issue because they figure it will only happen to someone else's kid.
I read an article that Canada is thinking about only allowing checking to continue in Tier 1 level hockey. The argument was that Tier 1 players might continue playing the sport at a high level but Tier 2 and below is mainly for recreation and fun. Some of the Jr B leagues are blood bath leagues.