Flavor-wise, it's heavily Tolkien inspired. By playing a human, you keep the fantasy races mysterious and rare.
Mechanically, demi-humans had lower level caps and were generally not as good as human equivalents (elves are sorta fighter/mage multiclasses; dwarves are weaker fighters with gold sense; etc.). Their function was to be played when you rolled bad stats. A bad statted character wasn't likely to survive to high levels anyway, so either way, they exit early and you roll a new guy.
If I remember correctly in AD&D humans did not have any advantage while the non-humans had all sort of bonuses unlike in 3.5, so Gygax gave them level caps in order to keep the world human centric. Why would you play a boring human if elves had sleep resistance, dark vision and could spot hidden doors without searching for them.
If you did not plan for a long campaign then playing as an non-human was not only ok but desirable.
Flavor-wise, it's heavily Tolkien inspired. By playing a human, you keep the fantasy races mysterious and rare.
Mechanically, demi-humans had lower level caps and were generally not as good as human equivalents (elves are sorta fighter/mage multiclasses; dwarves are weaker fighters with gold sense; etc.). Their function was to be played when you rolled bad stats. A bad statted character wasn't likely to survive to high levels anyway, so either way, they exit early and you roll a new guy.
If I remember correctly in AD&D humans did not have any advantage while the non-humans had all sort of bonuses unlike in 3.5, so Gygax gave them level caps in order to keep the world human centric. Why would you play a boring human if elves had sleep resistance, dark vision and could spot hidden doors without searching for them. If you did not plan for a long campaign then playing as an non-human was not only ok but desirable.