وَلَا خَيْرَ فِيمَنْ لَا يَأْلَفُ وَلَا يُؤْلَفُ emphasizes both sides of a healthy relationship: reaching out to people and being approachable through good conduct. In فِيمَنْ, فِي means “in,” and مَنْ means “whoever.”
Being naturally quiet or not making friends immediately in a new place is not proof of bad character. The important distinction is avoiding deliberate hostility, cruelty, and violation of others’ rights.
Example: a new student is reserved but returns greetings and offers help. Reserve alone does not amount to the condemned behavior.