I dunno about ambivalent. Tell a US person it's 30° outside in the summer and at best they'll give you a blank stare, at worst they'll say "well no it's gotta b

I dunno about ambivalent. Tell a US person it's 30° outside in the summer and at best they'll give you a blank stare, at worst they'll say "well no it's gotta be warmer than that out." They don't learn it, so no one uses it. If schools taught it then it might catch on. The food labeling stuff is for regulatory reasons, the only metric units US people actually use are liters for beverages.