To be honest, the only thing that I can see which would contribute to that pokemon being even mildly unpopular is how new it is. Also, Harrison, Lopunny is just not unpopular. I know a lot of people who like it, and not just simps.
You are correct. The person who added it noted that it isn't as popular as Gen 1 pokemon, but that only makes sense as it hasn't had as much time to gain popularity.
