Antonyms for "sing praises to" could include words like criticize, condemn, denounce, disparage, or belittle. These words represent the opposite of praising, highlighting flaws or faults rather than celebrating strengths or accomplishments. Other antonyms might emphasize neglect or indifference, such as ignore, neglect, or overlook. In some cases, antonyms might involve actively working against or opposing the person or thing being praised, such as in the case of reject, oppose, or undermine. By highlighting these antonyms, we can see the range of attitudes and behaviors that exist in contrast to expressing admiration and appreciation.