Categorizing risks by their impact on project objectives ensures that risk response plans are aligned with project priorities. This helps in focusing on the most critical risks and their potential impact on the project's success.
Categorizing risks by their impact to the project objectives is a way of aligning the risk management process with the project goals and stakeholder expectations. By doing so, the risk management professional can ensure that the risk response plans are focused on the most critical aspects of the project and that the project priorities are being considered in the decision making. This approach can also help to communicate the value of risk management to the project team and the stakeholders, as they can see how the risk management activities are contributing to the project success. Categorizing risks by their impact to the project objectives does not necessarily help to identify the specific causes of risks, determine the level of project leadership and organizational involvement, or assign risks and risk severities to functional disciplines and departments. These are other possible ways of categorizing risks, but they are not the main purpose of using the impact to the project objectives approach. References: PMI-RMP Certification Handbook1, page 9; PMBOK Guide, page 415.