Board Thread:Roleplaying Boards/@comment-26814804-20160511040026/@comment-26814804-20160516004942

Sans crossed his arms.

"hey, alphys, don't worry about it. the humans are just ignorant. or, uh, i guess so. i mean, i haven't known very many of them, and the few i have known have had a tendency to be pretty cool."

He noogied Frisk's hair. Frisk smiled and spoke up.

They said that on top of being ignorant, the humans also weren't very determined. As it turned out, almost none of the humans who lived on the Surface could lift more than 300 pounds. Since they and Undyne could tote around dozens of tons without much trouble, they'd be both useful and dangerous enough that the humans could forget their predjudice.