I get where you are coming from - and honestly, I may have not communicated properly. I don't necessarily disagree with you.
I don't blame a referee for missing calls, that is part and parcel to the game. What I do blame referees for is not adhering to the laws of the game. Let's put aside kids younger than U10 - very, very rarely do I ever see a kid sent off and I rarely even see cautions in the U11, U12, U13 age groups - although to be fair, they are happening more often as of late.
What I do see are referees that don't hand out the proper punishment (send off, caution) because...well, they are only young kids. Reckless and dangerous tackles happen numerous times in competitive U11-U13 games, way too much for my liking. Most of the time they are dealt with by calling a foul, but in my opinion just calling a foul is not enough.
I truly believe that if the laws of the game were followed more from the first year of select through U13-U14, we would not only see more free flowing games by the time kids reach U15, but we would have better players that would actually have to learn how to defend instead of just chopping opponents down.
I guess in short - a sending off is a sending off, whether it is U11 or U19, a caution is a caution whether U11 or U19 - but very rarely do I see them called the same way. For me, that is the issue.