Just to be clear, I'm not saying something that sets dex cannot be cheesed, but it isn't obvious to me how it outright breaks the game.
I didn't say it "breaks the game", e.g. like Stealth currently does.
In my first post I was explaining why I think this item type is poor design. Conversely, Gloves of Dexterity that would give +2 Dex couldn't be dump stat cheesed and wouldn't encourage counterintuitive builds, would never make a character's stat irrelevant, would never be stupidly OP giving a 10 point boost in an ability score, and would also benefit high Dex characters. Likewise Gale could power up his spells with a Headband of Intellect instead of it being useless for him.