Or, on the other hand, there is the other hand... a moisture farmer might, MIGHT lose a hand after 50 years of moisture farming in a freak accident while repairing a moisture vaporator without droid communication assistance...
Jedi lose limbs left and right, hands, feet, arms, legs, every other light saber battle they every get into...
So, maybe Lars was just looking out for little Luke's life and limbs for all those years... maybe not such a pr*** after all? 🙂