If asking for advice to truly help with a decision, it’s often useful to clarify that you want their full opinion, not just the PR-approved version of their thoughts.
The average person hates giving critical feedback to another adult.
The average person isn't qualified or skilled enough to give good critical feedback that is actionable to another professional, unless it's a direct mentor role.
E.g. I don't care about my manager's feedback, because he's not technical, and vice versa.
This kind of feedback just isn't relevant in most cases, so people just give their "PR-approved" thoughts, because everyone understands it.
This is kind of a crappy attitude to have
If the team accomplishes all goals on time and the client is happy, why does there even need to be feedback?
Don't make mandatory feedback some kind of misguided target.