I disagree with this practice wholeheartedly!!! Whenever they mention young ages at the assemblies I just shake my head in shame.
Have this close friend whose daughter wanted to be baptized at age 9, and then again at age 11, and I kept telling this girlfriend of mine to stall her desire in anyway possible. Thus far, the girl will be 14 soon and she's doing well in school and emotionally.
I just kept emphasizing the fact that it's not a good decision until the young person has been through puberty, that wild stage in which hormones go crazy.
I mean, if the Bible says that one shouldn't committ to marriage so young, then why should it be any different in making such a strong decision as baptism?!!!
I always kill my opinion opposers with the point that our Lord Jesus Christ gave us the best model; so, wait 'til your 30s!!!