Does this have something to do with building points or town points since I have like 12 beds and only 10 are filled.
An open world, base-building, adventure survival game with quirky humor and Llamas! · By
The little house in the top left is you base score. Every 225 (I know very arbitrary) you get a new one up to 10. You need to make sure you have beds for everyone though. That includes you and the NPCs you find/hire.
Also I haven't built in the 'live' spawning of them yet. You'll have to leave the base and come back to get them person to come.