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Why did people want Ash to have a rematch against Alain so badly?
A rematch is only fine if the first battle is 1-sided, so you get a training arc and then Ash gets to show how much he's grown.
Ash and Alain's final battle was already pretty even and Charizard was close to fainting near the end. A rematch would be pointless because the only thing people would care about would be the last 5 seconds where Charizard faints instead of Greninja