I think avoiding behavioral incentivization is impossible. You have employees. They (hopefully) want to excel in order to get things like promotions, raises, bonuses, praise from the creator of Ruby on Rails, etc.

You're inevitably going to incentivize their behavior somehow. I think it ends up simply being a matter of mitigating the worst possible outcomes, while angling for something that seems reasonably decent.

* Incentivize number of bugs fixed, and you'll get shitty code up front

* Incentivize number of features shipped, and you'll get a hodgepodge of features jammed into a product

* Incentivize peer reviews, and maybe you'll end up with a culture of glad-handers and politicians (I don't actually know about this one...I've never been in a corporate culture that embraced this)