It's funny, my experience is completely different. I've always loved to hire juniors because you can mentor and they usually come with less preconceptions. That makes discussions much more fruitful. And they usually make you think about your decisions much more, because they can challenge things that any engineer with experience with just take for granted or accepted.

The learning curve can be an issue though. You want to be constantly be welcoming newcomers to have a rolling scheme of new 'seniors'.