A good way to remove risk is to remove judgment. A rule prohibiting cash gifts eliminates the associated risks.
But removing judgment also creates risks when applied too broadly. Employees do not feel trusted and in turn withdraw their trust in the organization. The rules look stupid when they don’t accommodate for valid exceptions and management loses credibility. Employees become amoral in other areas where we want them to use their judgment.
Rules that remove judgment are necessary but they should be used sparingly and reserved for an organization’s highest risks.