Some people might have the understanding that if you are thankful, then you should just accept whatever happens to you in the form of silence. You should not criticise. Just be thankful, and be quiet.
I am unfamiliar with that concept of thankfulness. The concept that I am familiar with is that thankfulness motivates you to contribute. When you are truly thankful, you have this positive urge inside to give back. You want to contribute.
Contribution doesn’t mean that you are passive. Contribution doesn’t mean that you remain silent when something unjust happens. That’s what we call cowardice, not contribution.
Contribution means that you are adding something positive or you modify something negative into a positive. You make the world into a better place, however small your contribution is.
Providing constructive criticisms is a part of contribution. The intention behind a constructive criticism is I want you to be better. Even though the criticism might sound negative to the listener, but the motive is to improve, not to insult.
So when you receive a legitimate, well-founded, and ethically-expressed constructive criticisms from people, you should not tell people to keep quiet and just be thankful. Plus, that’s a bit ironic because they are constructively criticising you out of thankfulness, not the other way around.
People who are thankful should and will contribute to make the world a better place. One of their contributions to that end is to correct you when you are wrong. If anyone should be thankful, it is you.
You should be thankful because you have people who care enough to give you valuable feedback and courageous enough to voice it out. You want people like this around because they will keep you on track.
What you don’t want are people who remain quiet when you made a mistake.