I thought the same thing, so I checked the real paper and they do end up explaining their reasoning.
As for social interactions among humans, future research will explore whether the new study’s findings apply to women. “When we looked for volunteers who could donate tears, we found mostly women, because for them it’s much more socially acceptable to cry,” Agron says.
I’m interested if the results are same for male tears and also if they’re the same for women who smell either gender’s tears.