Are you talking about kind of upvote and downvote?
If so, here is a scenerio attached below. People will easily abuse the system by alt.
I don't think any kind of addition is needed in current system. It's working fine now.
This is clear OP that point system you were emphasizing will not going to work. It is being explained already in the qoute and I just may add a thought about this on the contrary of getting negative post will.be positive points or the upvote. Shitpost could upvote especially if you have lots of farm accounts to use to upvote your thread being moderated.
I get your point on getting rid of the spam post by self moderating the post. But, you can self moderate post without using point system. Just delete off topic and spammy post in your thread. This way you could help a lot with the MODZ.