When you receive something valuable from someone and you give them a sincere expression of appreciation, you encourage them to give more and often. It would be extra generous of them if you don’t show appreciation and they still give.
Free advice is something we all need time to time. Feedback received from a friend, colleague or relative is something that could lead to a great deal of self-improvement. Of course, you don’t have to follow whatever advice you receive. And you don’t have to accept every single feedback you get. But you always need to show appreciation. Appreciation is the recognition of their generosity.
Free advice is not really free. Like no gift is really for free. The person who gives it to you is, in fact, investing in you and in the relation. If they don’t see that their caring advice creates any positive improvement, they might eventually give up on you and even the relation.
The more we value the honest effort of such caring people the more we can receive their generosity.