Because it is personal. Other people do not know your goals or where you want to get to. Plus, are they much better than you? Do they have their own shit together? Are they saving enough for retirement? Are they working on multiple streams of income? Are they seeing their husbands and kids enough?
Even if so, do you trust them to put you first, or are they giving you things to work on that will benefit them rather than you? Even if, and that it's a big if to get to this point, all the above is true or irrelevant, are they any good at assessing what change will make a difference for you?
You can waste a lifetime trying to change based on other people's feedback, only to get conflicting feedback when your boss changes, you move department or change company to a different culture.
Gary Vee, as always, has a great way of thinking about other people's opinions in that he cares deeply what other people think and at the same time does not care at all.
How I see this is to care enough to listen but not to let it overcome who you are. You need other people's feedback to become self-aware but should not accept it carte-blanche or to act on it before assessing if you want to change in that area.
If Janet says you are too loud, it is not to be crippled by the thought, 'everyone thinks I am too loud, I need to be quieter.' It is just simply knowing, 'hmm, in the past, some people have found me too loud in certain circumstances. Do I want to work on this or not?'