It is a celebration drink. Paul chastized the once pagan Corinthian Assembly for coming together at Passover to gorge themselves on food and drink. He showed in 1Corinthians 11 that the Passover was a solemn occasion and not a festive time. It is a time for sober introspection, v. 28. Wine at the Passover would be inappropriate in light of what Paul was teaching about sobriety and humility at Passover.
Intoxicants simply have no place in a worship setting.
It is a byproduct. Wine is produced when yeast, a leavening agent, acts on the sugar molecule of fruit juice to produce ethyl alcohol and carbon dioxide. Wine, then, is juice that has been chemically changed into something different. It is not the original, pure fruit of the vine, but a secondary byproduct. As a symbol for the pure, uncorrupted, sinless blood of Yahshua, a modified substance like wine would be inadequate.