Some game systems try to provide "generic" rules that let you deal with different genres, ranging from high fantasy to galaxy-spanning science fiction to gritty cyberpunk to classical Greek to high-powered superheros. This involves dealing with variables on vastly different scales, with things like movement speeds, travel distances, and - pertinently - damage and armour. If you start with a game system that assigns a moderate amount of damage points to relatively advanced weapons - say 1d10 for a sword, or a pistol even - then any weapon which is less dangerous that that has to logically do less damage. And if there are several classes of lesser weapons, you end up squeezing the available space. And you can't assign an effective weapon a damage of zero, so the minimum damage per attack has to be 1 point.
In the first edition of (Advanced) Dungeons & Dragons, this infamously led to the statistics of a common domestic cat, as published in the Monster Manual II having an attack sequence consisting of a scratch with the forepaws for 1-2 points of damage, plus a bite for 1 point of damage, plus a special attack raking with the rear claws for an additional 1-2 points if the forepaws hit. This adds up to a total of 1-5 points of damage, assuming at least one hit in a combat round.
In this edition of Dungeons & Dragons, a normal non-adventuring human (say, a farmer) has 1-4 hit points. Which means that a domestic cat has a very good chance of killing your average farmer. In a single combat round. Adventurers are of course hardier stuff, and will have time to fend off the cat before it can inflict fatal damage.
Similar considerations can end up setting a high powered gun or other high-tech weapon to a certain amount of damage (e.g. a blaster pistol to 1d10), and then, independently, low-tech weapons to similar or even greater amounts of damage (e.g a staff to 1d12). Especially if the game designers don't check to see how the high-tech and low-tech rules work when combined.
GM: Han, Leia, you're pinned down by trooper fire.
[SFX]: Pow! Pow!
Leia: 3PO! We need some support!
C-3PO: My forrowers! Hit those troopers with sticks!
GM: That's not going to be very effective.
C-3PO: Well how much damage do they do?
GM: Let me check the Stone Age rules expansion. Stick, two-handed, hardwood: 1d12.
R2-D2: From behind is +3.
Han: That's more than my blaster!
[SFX]: Whack! Whack!
GM: Blaster, second-hand, dodgily repaired: 1d10-1.
R2-D2: I don't think these different tech level rules are calibrated against one another.
Trooper 1: Ow!
Trooper 2: Ow! Hey! Ow!
[SFX]: Whack! Whack! Whack!
Trooper 1: Aaargh!
Han: I pick up a stick. No, wait. I pick up all the sticks.
GM: You're not proficient.