The phrase "make a pitch for" typically means to advocate or promote an idea, product, or service. However, there are a variety of antonyms for this phrase, depending on the context in which it is being used. Some possible antonyms may include "reject," "oppose," "ignore," "dismiss," "disparage," or "deprecate." For instance, if someone were to make a pitch for a particular political candidate, their opponent may choose to reject or oppose that candidate. Similarly, someone may choose to ignore or dismiss a salesperson's pitch for a new product, or to disparage or deprecate the idea being presented. Ultimately, the antonyms for "make a pitch for" are varied and depend on the specific situation at hand.