In Hebrews 11 why is Rahab included in the “Hall of Faith” while the spies are not?

Hebrews 11 list a number of people that Hebrews 12:1 calls a "great a cloud of witnesses". Among them are the usual suspects: Noah, Abraham, Issac, Jacob, Joseph, and Moses. But there are also some lesser names, including Abel, Enoch, an...