This summary is not the rule. The rule text controls.
Lawyers are allowed to criticize judges and other legal officials, but they can't lie about them. This rule says a lawyer cannot make false statements about a judge's qualifications or honesty if the lawyer knows the statement is false or didn't bother to check whether it was true. This applies to judges, other court officers with decision-making power, and people running for judicial or legal office.
The idea behind this rule is to protect the public's trust in the legal system. Lawyers have a lot of credibility when they talk about legal matters, so false attacks on a judge's character can do real damage, both to that judge and to how people view the courts in general. This rule doesn't stop lawyers from making honest criticisms or raising real concerns about a judge's conduct. It only stops them from making things up or spreading claims they haven't bothered to check.
If a lawyer decides to run for judicial office themselves, they also have to follow the rules in the Code of Judicial Conduct that apply to candidates. This means they have extra rules to follow beyond just the normal conduct rules for lawyers, since they are now seeking a position of public trust as a judge.