There are so many ways to earn merit.
My case for example. I have 25 posts and 17 merits. Why? Because I interact with people, making jokes, answering questions, etc..
We don't need to grab some stuff from elsewhere and post here to earn or prove something.
You can joke or reply only when you understand context of any thread. The user OP mentioned created his own questions and replied on his own as he did not even have the ability to understand anything. But, he was trying to spam by playing those cheap tricks.
It is to be noted that the moderators ate awake and alert to maintain the discipline. His tricks screwed him off. That is a less to all other scammers.