Did the Jews think it was immoral to have leprosy?

> He stretched out his hand, and touched him, saying, “I want to. Be made clean.” Immediately the leprosy left him. He commanded him to tell no one, “But go your way, and show yourself to the priest, and offer for your cleansing according to what Moses commanded, for a testimony to them.” (Luke 5:13-14) This indicates that Jews (including Jesus) thought illness is a punishment for your sins. Is that true? It seems to exclude today's basic Christian understanding.