Sloom
sherb
It is usually just because the more popular villagers have a unique look to them, because to be honest, you can't judge a villager by personality. There just aren't enough personality types for that. Ones like Julian or Pietro are special because you cannot get another sheep or another horse like them, and their designs are very appealing. Who doesn't want a rainbow sheep or a blue unicorn that flirts with them in their town?
Another thing is just basically what the others said. If it's popular, I must have it. It definitely will impress people who visit your town if your village is full of expensive/popular villagers.
Personally though, most of my favourites fall under the "Almost there" or "Middle of the road" category. But to each their own. I can't deny liking some of the most popular villagers just because of how unique and beautiful most of them are.
Another thing is just basically what the others said. If it's popular, I must have it. It definitely will impress people who visit your town if your village is full of expensive/popular villagers.
Personally though, most of my favourites fall under the "Almost there" or "Middle of the road" category. But to each their own. I can't deny liking some of the most popular villagers just because of how unique and beautiful most of them are.