Always positive — describes people who are genuine and unspoiled by city sophistication, or rural communities, traditions, lifestyles. Often paired with
民风 (folkways) →
民风淳朴 "the local customs are honest and unspoiled," a fixed phrase you'll see in tourism writing. Don't confuse with
朴素 (pǔsù, plain/unadorned, used of objects and clothing) or
单纯 (dānchún, naïve/simple-minded).