The term "unreached" was made popular by mission leaders seeking to prioritize ethnic people groups with little or no exposure to the Gospel. Today, the term has become a catchword used by all kinds of ministries that do not necessarily focus on unreached people groups.
Ignorance is bliss but it can also be deadly. One of the most dangerous misuses of Christian phrases I’ve heard recently is the overuse of the phrase, “unreached people group.” I’ve heard people use that phrase to talk about efforts to reach college campuses, friends, clubs, and neighborhoods. It is a term that has been used more and more in the Christian subculture to validate missional status quo rather than raise the alarm for people groups who are entirely cut off from the gospel.