When I'm an interviewee I do the same thing. Opportunities to get interview feedback are already scarce, best to maximize them with questions like this.
When I'm interviewing, I always do a portion at the end to tell them at least one thing that impressed me and one thing that gave me pause.
When I'm interviewing, I always do a portion at the end to tell them at least one thing that impressed me and one thing that gave me pause.