They usually prefer to hire new grads for 3 major reasons.....
1) They believe new grads haven't developed bad habits or learned to do things differently than they prefer to have them done, which requires retraining. Seasoned nurses have often seen more and developed their own way of doing things which might not be wrong, but may not be the same way a new employer wants it done.
2) They don't want to pay us what we're worth. Experience means more pay. They'd rather hire someone new who won't insist on a higher rate of pay than what they're initially offering.
3) As we gain experience and knowledge, we become less likely to accept being mistreated or overworked. We know it's okay to say "no" and stick with our guns. New grads are more likely to accept less than optimal working conditions regardless of the discipline.