I saw somebody (attempt) to use similar logic to describe the character a certain person would prefer.
Dexterity. Every two points of Dexterity gives you a chance to get some extra To Hit every level up.
Strength. Every two points of Strength gives you a chance to get some extra Attack every level up.
Vitality. Simply gives you HP.
Why would you invest in Vitality early on, when your character's attack will be gimped for an early increase in HP? Vit directly correlates to an HP increase, but if you take STR and DEX later in the game, you won't see a large benefit from it, since you need to have it before/as you level up.
Now back to how the mechanics actually work, why is one statistic being singled out and why is a "don't do these rolls randomly" button not a great idea?
Before you say anything no I don't save/reload and I probably won't, but I have always really hated the random, permanent, rolls that have been weeded out for years. They were alright in Wizardry which had grinding, but in a limited, almost puzzle game like LoG, it just doesn't work for me. Losing is only fun on Dwarf Fortress.

(my first attempt, one of my two identical fighters had TWICE the HP of the other. Go figure.)