Most Helpful Guy
Looks can be a factor, but once you get past the superficial stuff, I think it comes down to guys doubting that they have anything to offer that the girl would be interested in.
Most Helpful Girl
When I was in my early 20s me and this guy were really good friends and we had great chemistry. Everyone said we should be together, but he confounded in a friend and said he thought I was too good for him so that makes sense.