Looking through the Diablo 3 tags, I noticed that we have a tag for Reaper of Sous on computer, but not console. After looking further, it appears that the tag diablo-3-reaper-of-souls links back to diablo-3. Furthermore, there is simply the tag diablo-3-console, where both Diablo 3 and Diablo 3: Reaper of Souls editions exist on console.
I stopped playing on computer long before the expansion was released, but they must still exist as separate games, otherwise they would not sell each version individually. While the biggest change is going to be content unlocked with the addition of the expansion, and most of the game is the same, they are still two different titles.
I know that on console, the two versions are very different. Questions could be asked about one that would not make sense regarding the other, and questions could be asked where version make a significant impact on the answer.
Why do we tag Diablo 3: Reaper of Souls as Diablo 3?