The policy isn't necessary to close the PR. The policy just helps to shut down the ensuing discussion after closing the PR. It helps in quickly dealing with well-meaning onlookers asking for clarification when you block PRs from the account.
These days large PRs are easy to create and so humans need to shut them down.
Or, put more bluntly, your belief in what people ought to feel entitled to has no bearing on what they do believe, and policy needs to address the latter, not the former.