[Bullet Magnet]

How about: every single monster raising/fighting game in existence? They all involve taking innocent, sentient and in many cases sapient beings, often from the wild, and after forcing them through rigorous, strict and abusive training regimes, pitting them against each other in a bloody fight, in some cases to the death. Jade Cocoon is probably the worst for this: although you are morally absolved from the capturing, training and battling parts with some very clever backstory details, your only source of income requires the spinning of your creatures into oblivion in order to sell the silk of the cocoons that their spirit is sealed within.

All these creatures seem to accept this lifestyle as it is presented to them quite happily, and their loyalties change like the wind, but by Jove, if they don't have any other career options once the humans turn up.

Still fun, though.