I think it is cute how they have NPCs refer to the rarity of Pikachu, he was relatively tricky to get in the Gen 1 games too.
Having a stick doesn't necessarily make him old, he may have got injured when he had to relocate his Gym.
I've never used the Grumpig line, Sunflora Line or Gogoat Line. I have never owned a Shaymin or Meloetta but I have used every other Psychic or Grass-type at one point or another. :)