I watched at least one episode of every show in the title.
Here's why I think they are on the air:
Adventure Time was/is doing well. It is a lighthearted cartoon.
Young Justice didn't do too well (when it came to selling toys). It was a heavyhearted cartoon.
CN thought to themselves: "Hey, you know what? We should air more comedy shows and stop airing action shows, because goofy = good!"
What they forget is that Adventure Time wasn't successful simply because it is lighthearted. It is a mixture of action, romance, drama and pop culture references. Every episode is different and written well, except for several weird ones.
I honestly would like to see DC obtain their own channel, keeping it afloat with reruns of DC shows and movies in the beginning. Then they would air new superhero cartoons without the fear of them being canceled by CN because they weren't goofball cartoons.