So what is inhibiting feedback?
Fear of Consequences
Fear of Alienation from Colleagues
Trust (Or Lack Of it) in Your Manager or Management in General
Suggested reasons for the “trust deficit” are management actions inconsistent with the mission and vision of the organisation, an emphasis on productivity and achievement at all costs, excessive turnover and continuous change, leaders who use ambiguity in their promises, managers who make promises that are not fulfilled, being economical with the truth and management that does not observe sanctions when trust is violated.
Lack of belief anything positive will be done
Neglecting an understanding of any of the above motivators is almost certain to condemn your attempts at creating an open culture, and benefiting from valuable feedback, to failure. After all understanding is the first step on the road to changing.