Did you expect young people, who aren't used to the forums, to stand in line like the rest of us?
From my experiences, young people are just like this outside of the Blockland forums, but it's more noticeable since you don't normally see this number of screaming kids here.
As Blockland gets more popular, a relatively larger audience of young people will probably be attracted to the forums, resulting in an even more noticeable younger population on the forums (assuming they don't quit the forums or get banned).
I would assume the new young people on the forums who are making these posts want the attention they got with whoever they were with outside of the forums, like their parents or their friends, or they noticed a new place for them to be in, and are trying to show the rest of the community that they think they can be a part the community, to show the rest of the community that they can be like everyone else.