Why do Suggestion schemes fail in the organization?

Why do Suggestion schemes fail in the organization?

Suggestion programs are formal plans to invite individual employees to make suggestions for work improvements. The suggestions are then sorted out as per their applicability. The emphasis is on individual commitment rather than just group problem solving and teamwork. There is a possibility that employees may feel delay in the processing of suggestions or if certain ideas that appear good are rejected, then the employee may stop making suggestions in the future. Some managers find it hard to accept suggestions from their subordinates and also at times, consider it as a criticism of their ability and practice.