I don't think he had an issue with jumping, but more an issue with the platformer style of play in the Remanent Vaults where you have to jump from one pylon or platform to another and if you miss you die. To him it seems to be a game style preference, which I can kinda understand, but can't agree with him on. Now mind you it is his preference, but I can see the value of the platformer mechanic to add difficulty and puzzles to the game. Once I spent time with the game, it wasn't hard and was just another puzzle to do, and his argument can be used against just about any element....well if you fail just reload a save so why have it there.....
Though as a yeah, game logic note: you can fall out of the sky pretty much from lower orbit, you can use "gravity wells" to traverse levels, but if you are in first Vault, and jump off the edge to what you can physically see below, it kills you.....cause you ain't supposed to go that way.....game logic.....