Because runoffs already exist in a lot of places around the US, and IRV does accurately describe what happens if you are comparing it to a runoff election. I ag

Because runoffs already exist in a lot of places around the US, and IRV does accurately describe what happens if you are comparing it to a runoff election. I agree that "ranked voting" is a better term in a vacuum (and probably a better term regardless), but since there are more people in the US who have been exposed to runoff elections than ranked voting, I understand the choice.