It is exactly an early editions of Dungeon and Dragons thing. One of the things about early DnD is that the world that the game created was dominated by humans, and so player choices and restricitons were made to both reflect that fact, and also for game balance reasons.
In the cool/interesting video thread, I shared a one video from channel Daddy Rolled a 1. The owner of this channel often takes a look at things, mechancis, classes, monster etc. from early DnD and explains why they were made like they were, how the change throught different editions etc. What I said paragraph above was a short version of what I've heard there.
