Do you understand basic physics? 6 years olds, no matter what, are not capable of inflicting that sort of damage. They do not have the required momentum. I have nephews, who, as kids, took tumbles all the time. It's pretty much the same. Both are on pace to get into Ivy League schools. Didn't affect them, one bit. Not to mention the fact that they had injuries where they broke their noses, etc..
Again, I posted actual research which when into it. You're using an opinion as your argument.
From my article, which was ACTUAL RESEARCH:
When it comes to concussions, for 8-13 year old kids, there was a 0.067% chance of a kid getting a concussion.
When it comes to serious injuries, for 8-13 year old kids, there was a 0.14% chance of a serious injury.
Injuries in general, for 8-13 year old kids, was 0.26%.
The risk of actual injury for both tackle and flag football is a whopping 0.27%.
Again, this is not a small sample size. This is a sample size of 44,164 kids who played tackle football. Flag football pretty much doubles the injury rate though. Something which is still negligible.
As I said, kids at their ages (the ones posted in the twitter link) are not even remotely close to being able to hit hard enough to inflict actual damage. Basic physics and biology.
Please go through this article: