My guess is that, at first, the whole idea was pretty hard for Paul to take. Paul once cherished a personal success and achievement in the law that humbled the ordinary person. After his conversion, he may have placed a great deal of confidence in his own ability to succeed at his new mission. Jesus was amazed at the lack of faith in Nazareth. Times haven't changed.
Many people still come to church to be reassured in what they think they already know.
When Jesus confronted the assumptions and challenged the ideas, attitudes and behavior of the folks at Nazareth, they rebelled by attacking His credentials. Apparently these people were as averse to repentance as we are. When we read the story, it is difficult to put ourselves in the place of Jesus' friends and family. We cannot picture ourselves taking offense at Him. But the family of God continues to take offense at Jesus whenever He confronts our sin, our presumptions and our prejudices.