Things renters can and will do include not pay rent, incurring several months (or worse) while being evicted, trashing the house.. if they behave badly or just can't quite keep up with timely payments and you have to rollover to a new renter that is pretty expensive, too.

This isn't to say credit scores are perfect, but they are so effective a predictor of conscientiousness, insurance companies rely on them to predict someone's likelihood of a car accident - on average, they work.