The argument is that since the numbers between 0 and 100 are sacred, as proponents of both metric and imperial temperature scales agree, that the system that centers that range more evenly over the range of temperatures experienced by humans is preferable, and wastes less numeric precision on common temperatures.

This is flawed because it turns out that 1) people can comfortably use a wide enough range of numbers that it doesn't matter and the value of the system you are used to far outweighs the saved handful of syllables and 2) people don't communicate about weather colloquially with enough precision or accuracy for any possible advantage to actually matter.

There are only two reasons to use one system over the other, and they're both consistency. Consistency with the rest of the world, and consistency with itself.
Everyone else uses metric, so we should too. It also uses a system, as opposed to a combination of every 14th century tradespersons system.

With Celsius, you can't walk outside and exclaim in horror "It's a hundred and 20 fucking degrees!". "It's in the negatives." doesn't carry any weight either.