Regardless, the “pedantic” argument against the headline is only a thing if you’re not allowing for the evolution of language, it’s actually just being a snooty language snob given that language does evolve and the usage of the headline aligns with common standards these days:
Decimate strayed from its “tenth” meaning and nowadays refers to the act of destroying or hurting something in great numbers.
Regardless, the “pedantic” argument against the headline is only a thing if you’re not allowing for the evolution of language, it’s actually just being a snooty language snob given that language does evolve and the usage of the headline aligns with common standards these days:
See also definition 3b of the same source.