So humans feel cold at 0F and hot at 100F?

In aggregate this is absolutely true, though not the point anyone is making.

Humans start quickly dying at something around 32F and 180F

Humans will die of dehydration or heat stroke quite quickly at temperatures well below 180F. In fact that's far hotter than the hottest recorded temp on Earth (~135F/56.7C) (not including human-made environs like a sauna or outliers like an active volcano) so I'm frankly not sure what point your even trying to make here.

Fahrenheit is complete nonsense. It has nothing to do with humans.

The latter statement is manifestly false. Fahrenheit was originally supposed to have 90 degrees as the average humans body temp (no clue why 90 and not 100). Due to inaccuracies in measurements of the time, It was later changed to 96 and then 98.7. Still no clue why not just 100, but the fact remains it was based on human body temps. The zero point was selected using the freezing point of a brine mixture. No real defending that one, it was pretty much arbitrary.

And considering humans are mostly water Celsius seems a much better fit.

But we aren't just water. In any case, humans are rarely at boiling temperature. My ideal temp scale would have 0 at water's freezing point and 100 at a humans body temp.