>>19776028Because HGSS included it as a feature even though it wasn't in the original version of the game. A lot of people were speculating that it would be included and have Pokemon Amie integrated with it. In HGSS you could turn around and talk to your pokemon to get a text blurb of what it does and how happy it is. Most of us thought you'd be able to turn around and talk to the pokemon to initiate Amie. It would make tons of sense.
Now that they have all the battle models created, the next game could easily have put in the work to do some simply animated overworld models for all the pokemon to allow them to follow, but apparently they didn't have enough time before they released ORAS. I'm holding out hope for Delta Emerald/Z version to have the feature though. Time will tell.
There's enough fan demand for it that if it isn't included by at least the next main series entry then Gamefreak is truly just not paying attention.