Should employers conduct job interviews a public place? (Places like a cafe)

If you have an office with a conference room or your own office, why go to a cafe or in a public place? When I've done interviews for a position, I generally had 2-5 candidates come in to interview. And since the interviews were all staggered you generally need a place for other candidates to hang out while waiting.

it's certainly more relaxing than being in an office setting. I've had one in public and it was my best!