- be seen by voters as beneath the official’s dignity,
- be seen by voters as improper attempts to suppress criticism (even when the official has a good argument that the criticism is false),
- amplify the original allegations, because articles about the lawsuit will mention the charges that are being denied,
- distract the public from the substantive messages that the official might want to promote,
- lead to discovery requests that might uncover potentially politically damaging evidence.
But of course President-elect Trump is not the usual officeholder.