Originally Posted by -Starly-
No, it's because the writers are lazy and don't want to draw a diferent one-episode character for a nurse or a police officer every single yime one appears.
It's not that. I think the reason for them not drawing a different nurse for all the episodes is because;
1. ideas would run low and it would become very difficult
2. the games came out before the anime. And in the games, every Pokemon Center had a Nurse Joy. They couldn't change that.
As for the Jenny's, I tihnk they decided to place the same concept on them as they did with the Joy's.
But this is all based upon one Meowth's opinion.