From time to time my company gets emails that go something like this:
Your web site is awful! and I hate it. I could not place an order because it was so dumb. You have lost me as a customer.
Luckily we don't get these kinds of emails very often, so when we do I like to take a few minutes out of my day to respond sincerely. Deep down, I know they're probably a troll, but I like to give them a chance and I treat them like an adult.
I'm really sorry to hear that you had bad experience with our company and that you dislike our design. We always want to provide the best experience for our customers. If you are willing, I would love to get your feedback on our site so we can improve it!
Was there anything specific that you found difficult, broken, or unintuitive?
I had a lecture class in school with a really great teacher. There was a student who thought they knew better than the teacher and was always trying to make comments and critiques on how they were teaching. Eventually the teacher said "next week, you should prepare some materials and you can lecture the class". The next week came and the student was horribly prepared and only made it 10 minutes into the "lecture" before they ran out of material realizing that giving a lecture was much more difficult than it had appeared.
In my three years of responding to these troll emails I've only had one person actually respond with real feedback. And that one person had some good ideas and we incorporated into our design and experience!