Maybe they thought it was encouragement, "don't worry mate, it's not your fault" sort of thing. Seems somewhat ill-conceived though.
what is a disadvantage in some situations is an advantage elsewhere.
I know long and short, thick and thin climbers, and male and female ones come to that. And they all approach problems differently, but I'd struggle to say one is better. I've a mate who's five foot not much but a stocky little sod, all upper body strength. He'll power through a crux move whereas someone six foot plus might get away with skipping that tricky hold completely and reaching straight for the next one. And my OH is a bigger girl but ever so bendy, I've seen her hook a foothold at head height and manage to lever off if whilst all the lads went, "wait, what? How?" Different people have different strengths and what works for one isn't necessarily optimal for another.
One thing I've learned over the years introducing friends to climbing is that you can never tell what they're going to be like until you get them to the wall. I've taken people I thought would struggle and they've turned out to be naturals; I've taken others that I thought would be really good and they've not got off the ground. Quite interesting, I think.