They're paying with their time, and I have questions I want to ask them. It's a mutually beneficial experience. Being told "here do this arbitrary thing that w

They're paying with their time, and I have questions I want to ask them. It's a mutually beneficial experience. Being told "here do this arbitrary thing that will take 4 hours of your time and maybe we'll look at it, and then if we even bother to do that, maybe we'll respond" is different than an interview where both parties invest their time face-to-face.