Well, because of my lack of labor force in almost every single harvest season, I would rather just let them eat, instead of suffering from crop spoilage. I view the crop-stealing deer as natural fur farm. I trade crops for furs and some extra protein (the poor 60 meat is unnecessary though). Moreover, wolf dens play the same role in my game, I’ll plant lookout towers near the wolf dens and then gain dozens of furs before I have to destroy them to take room for village constructing.
To be honest, I do that only because the fur-meat-ratio of cattle is too low. If I slaughter 30 or more cows per year to meet my fur requirement, I have to waste a lot of fresh meat.