Also your never sure what answers you'll get. Sometimes they sort of answer the next question that you have in another question so you don't want to ask the next one. You want the interview to feel organic and not as if you're reading off 4 X 5s.
In addition as grapeviney mentioned we're cognisant of the time and we don't want to overstep what we've been allocated. Thankfully every guest we've ever had has had no problem answering and going over the allotted time.