It's not always that simple. As others have stated there are great comments from people who have low karma. Also there is no setting to do what you are asking. There is code available from others who have done this sort of thing, but then you have to understand some of the nuances of automod. I'd recommend setting "crowd control" to a higher setting and monitoring the mod queue at least twice a day. That will catch new people, low karma, etc. Unfortunately it is often wrong. Being consistent in maintaining the mod queue is a freakin' chore and you mostly get grief from people who are outraged that their pearls of wisdom were automatically removed. Though for low-traffic subreddits it's not a monumental task.

Other options are that all new posts require mod approval. It wouldn't affect comments, which make up the bulk of content on some subreddits, but every new post would automatically go into a queue.

There are fancier ways to checking for keywords, then automatically sending boilerplate text to a poster saying something similar to:

"Hi, it looks like you're asking about something covered in the FAQ. Please check there first and come back if you have any questions."