It's good to know the person very well and what he does for a living before selling bitcoin face to face to the person. I only sell bitcoin to family members or very close friends who don't know how to buy from an exchange because they're new to the cryptospace. However, bitcoin is becoming valuable overtime and physical p2p should be discouraged in order to keep your bitcoin involvement a secret and safe from attackers.
Theirs nothing bad to sell your bitcoin to someone you don't know through p2p, because the transaction is there and what both of you did is exchange of goods and the services so I can never be afraid to sell my bitcoin to someone that I don't know provided that the person how they physical cash to give to me I will send my bitcoin to the person I don't know why all the reason why I should be afraid of my business, even someone who knows exchange where to buy Bitcoin can equally decide to get bitcoin from someone who want to sell directly without selling from Exchange so it is a personal decision of anyone who want to sell Bitcoin