When I was a mormon I was baptised at age 8.
As witnesses some get baptised pretty close to this age.
When they face all those years ahead with so much of life to learn and understand how can it be right to come down so hard on young people who, when going thru puberty and beyond have to come to grips with all the feelings and mixed up thinking of youth and then fall short of the ideal and ,say ,fall in love with someone and have sex and then face a judicial commitee.
Everyone is different and it's naturally easier for some young ones than for others due to alot of factors and keep on the straight and narrow.
But here is my opinion on things, simply put , Jesus as a perfect man was not called upon to dedicate himself for baptism and full dedication to God till he was 30!
Is it not reasonable to expect the same from imperfect people led by sinful inclinations to make a mature decision when older at 30 instead of a teen or even a preteen and expect full control and even repentence?