The problem arises when one of said adults playing with their friends decides to be a sourpuss and report the chat, in which case microsoft moderators have absolutely no context on the server's group culture nor what was really going on, and they won't bother digging deeper.
At the end of the day individual servers are completely separate worlds that you cannot moderate as a whole due to differences in rules, expectations of their members and culture. You cannot moderate all of that by throwing a blanket rule system over it. Even the unofficial global ban system before this, mcbans.com, had a system to allow servers to only honor bans from specific other servers who they aligned with.
As for children I recommend keeping a mildly distant eye on what servers they visit, and this doesn't just apply to minecraft. As a kid I had a rule with my dad to consult him first about any terms of service I wanted to accept (for example for forums), so he could make sure it was safe. This worked until I became a teen and specifically started seeking out the bad things about the internet, but at that point no public ban system is going to help.
At the end of the day individual servers are completely separate worlds that you cannot moderate as a whole due to differences in rules, expectations of their members and culture. You cannot moderate all of that by throwing a blanket rule system over it. Even the unofficial global ban system before this, mcbans.com, had a system to allow servers to only honor bans from specific other servers who they aligned with.
As for children I recommend keeping a mildly distant eye on what servers they visit, and this doesn't just apply to minecraft. As a kid I had a rule with my dad to consult him first about any terms of service I wanted to accept (for example for forums), so he could make sure it was safe. This worked until I became a teen and specifically started seeking out the bad things about the internet, but at that point no public ban system is going to help.