I'm saying that 0F is waaaaaaay more dangerous than 100F so the logic of those particular temperatures being the 0-100 ends of the scale can't be explained by how dangerous they each are.

Almost everyone would be fine staying outside for 30 minutes at 100F without no external help (shade, cool drinks etc). Almost nobody would be fine after staying outside at 0F without external help (parka, thermals etc).

To me, with absolutely no data, it feels lie:

• 0F is as dangerous as 140F (you're long dead if you're outside in both cases)
• 100F is as dangerous as 40F (mildly uncomfortable but safe for a while)

So calling 0F and 100F both "really dangerous" and using that to justify them being the respective points of 0 and 100 disingenuous. Like, use Fahrenheit if that's what you're used to - I use it too because that's what I'm used to. But I don't explain the insane system with "it's because the two ends are reallllly dangerous."