"More often then not the designers who complain that clients give them subjective feedback are the ones most prone to asking for subjective feedback. Everyone gets the feedback they deserve.
Stay away from questions like 'do you like' you weren't hired to make something they liked. Ask your clients to comment specifically about the things you want them to address. (What you need to know). Avoid talking about the things you don't want them to go into.
They will, of course, still give you feedback about things you may not want feedback about. Most of it you just need to hear and acknowledge. But if they're persistent, ask them to map what they are asking for a goal, and follow up with clarifying questions. Oftentimes a client's prescriptive feedback needs to be unpacked to get to the real issue."
– Mike Monteiro "Design is a Job", 72