I think the article touched on many true aspects as to why Taeyeon's so popular. To be honest, when i first noticed SNSD, i didn't know Taeyeon was the leader at all, let alone the most popular (for some reason i thought it was seohyun because she was in the center lol). But this was in their performances, and i didn't really think she was 'THAT' pretty (

But after watching her in variety shows and the girls' shows, she very VERY quickly became one of my fave 3 members. I contribute it all to her dorkiness/personality.
And tbh, i think that when people 'discover' a pretty person through their personality, that person would be more special than ones that are just pretty through their looks. It's the whole package sort of thing?