Debate brings opponents issues to the forefront and expression, concisely and quickly. Satisfying emotions of anger and righteousness, debate resolves and brings to the forefront issues the parties are concerned with and disagree on. In disagreements there is potential for problems to fester and create ill will among parties. Debate lets the opponents express their disagreements in a civilized way and formal way. The formal structure keeps emotions from overwhelming the debaters. Debaters have a platform to express their views and how right they are. They get to see immediately in a debate format the problems and issues with their position. By keeping emotions from overwhelming either party debate formats create more good will than ill will and are much quicker than a dialogue.
No, dialogue is better than debate for emotions, spirit and virtues, because dialogues make people work together to come up with positive solutions that everyone can agree on. Dialogue makes people think of creative solutions, rather than just focusing on being right. Dialogue is less threatening, and people do not feel painted into a corner.