Elder Millennial here. I think I just have that “eww pedostache” reaction because, when I was young, such mustache styles were common among middle-aged men who hadn’t updated their styles since the '80s. Some of those men were creepy, so the mustache style became associated with creepy old men. And of course, teenaged giggling among ourselves about “eww pedostache!” really cemented the association.

I’m pretty sure our parents had the same initial reaction when we brought aviator glasses back into fashion. We’ll get over it, the cycle continues.