I was thinking that merit system have created for rewarding users who're sharing valuable contents with the community. It seems I'm wrong... merit system is possible to use for rewarding jokers as well.
You can give merit on any post if you like the post. And your point is also partially right. On Facebook, there was only like option but now it has given a few others sad, love, etc. As for sad news, we gave like on the merit system we can use our merit if we like the post.