Originally Posted by
Cilia
The First doesn't use the term "beastman" / "beast tribe," as that was mostly a construct created by wealthy Ul'dahns to discriminate against peoples that don't conform to Eorzean standards (worship of the Twelve, etc). The Doylist reason for it is the game originally had many similarities and parallels to XI, which actually did have significant differences between the races of man and beastmen, but once Yoshi-P took over from Hiromichi Tanaka they had to explain and recontextualize all that stuff in order to push the game out of XI's shadow.
Tellingly, "beast tribes / beastmen" have been discriminated against less and less as the game's gone on, with Heavensward featuring mostly peaceful unless under a primal's thrall beast tribes, Ananta being integrated to a degree into Ala Mhigan society, and no distinctions being made between the two in the Far East or on the First.