Entertainment becomes art.
Art becomes commerce.
Why put emotion into games?
The answers are: art and money. Sure, it's an unholy alliance, but so are pineapple and pizza, windmills and tiny golf courses, military intelligence, and fruit and Jello™ molds.
Don't get me wrong. I think of myself as an artist first, a businessman second. Game companies that don't make a profit, however, aren't game companies for very long.
There are at least nine reasons why putting emotion in games can lead to greater profits, and it's worth taking a few minutes to mention them.