If your opponent does it, you should do it too. Even if it's just for a half and then beat them in the second half. None of us want to play 25 games of mut champs. For some of us the rewards literally stop after stat objectives and 7 wins. As a community just help each other finish the dumb objectives quickly so we can play seasons. being forced to play mut champs is terrible, it's not weekend league. Nobody cares about your 24-1 mut champs record.
If you can find a good reason not to help each other out I'd love to hear it.