When expressing one's negative opinion on a particular action or behavior, it is often necessary to use strong language to emphasize the harm it causes. One such phrase is "doeth disservice to", which means to harm or undermine a person, group, or cause. However, this phrase can be replaced by a number of synonyms to add variety and nuance to your language. Some alternative words or phrases include "undermines", "hinders", "does harm to", "discredits", "sets back", and "compromises". Using different synonyms can help to convey a more specific message or emotion, and make your writing or speech more impactful.