App uncompatible

When I was want to use Uber App in my iPhone 4 with iOS 7.1.2, i wanted use the last resources of the last version of the app. But i needed download the last compatible app from itunes in my iphone 4 with 7.1.2, my question is which the reason to end support for iOS 7.1.2?

Onairda1996 about Uber, v3.241.2