Receiving feedback is something so vital that can help to decide the course of your entire business.
Whenever we're talking about voluntary user feedback (feedback or suggestion forms, polls, focus groups,...) or indirect feedback (metrics, profiling, tracking, A/B testing,...) we should listen to it because if users are not happy with our product, they will end up leaving us.
I've seen at work (back when I was working in the mobile team) how user suggestions can provide a steady growth per month in pageviews and user satisfaction. How users can mold part of our future projects with their suggestions and critics. How to grab so many ideas for quite a few months of work, not counting our own company projects.
Of course you have to be realistic. People always want more, and a lot of times they don't know that they don't really want something: Having 200 different components can for sure display everything "at once", but you will need to scroll until the end of time. They might want to see three photos at once from their mobile phone, but if we did that then those images would be smaller than a single one, and would require between 2x and 3x times to load...
So gathering all feedback as possible is important, but having in mind that it's only information that you might use or not ;)
After talking about how great and important feedback is, we have to face a problem: The fact that we are humans, and like most humans, we don't want to be told that our work is not correct.
It might be an improvement idea, a personal suggestion, a random rant, an experienced advice, a joke, or a troll. But the fact is that our usual reaction to "why don't you do this that other way?" is "yeah, whatever" and try to discard or combat it.
Our code is perfect, our web design is the most beautiful, simple and UX friendly one ever created, our scripts are flawless... We are experts, we always do things the right and most experienced way, and we don't need advices because we're the best in what we do.
Or at least that is our hidden, subconscious reaction.
A lot of times there is some hidden message in those feedbacks. Maybe something is misleading people to think incorrectly. Maybe your solution is ok but there is a faster one that you didn't knew about. Maybe one in a hundred feedbacks gives you a wonderful idea for a future improvement.
Bad feedback is better than no feedback, and we're all mature enough to either discard useless negative comments or extract the implicit message and discard the words used to express it.
And sometimes, receiving hard critics just make you stronger. If you believe in your code, in your tests, in your work, stay firm and ignore bad words until they actually have some proof. But that is a subject for another post ;)