That feature is brilliant and beautiful! Makes the whole concept of "raising" Pokemons way more realistic. Plus, it's really fun to win the grass gym in Kanto, when your whole team but your grass starter fainted, then see that one following you XD
Like watching the Charizard-Magmar match in the TV as a 6~ years old child again~
Oh and, laziness or not, I love the fact that the Pokemons are still walking when you stand still. I thought about it deeply, and with those nerfed sprites compared to, let's say Mystery Dungeon, it could look very robotic if the Pokemons was just standing there when you stood still.