I think of it this way.
If you're 10, a typical lego-loving kid, and you're on the internet looking at lego stuff, are you going to be attracted by a game like Blockland? Of course you are. This game is practically made for kids, but we take it to a different level.
We shouldn't really hate kids in general just for being young, but if they're being immature (most of a 9 year old's jokes aren't really that funny), then that's different.
I'm 14, by the way.