Refuse to arbitrate is usable in other cases
The guidelines say to "not rule in favor of a side who have engaged in immoral activities" immediately followed by saying to refuse to arbitrate should be used in these disputes. It's not saying it cannot be used in other cases.
In fact if there is a tie, the court will say the jurors refused to arbitrate as the ruling, even if there were no immoral activities. That proves it's not the only way.
If a case is a tie, makes no sense, or shouldn't be in the court, wouldn't it make sense to refuse to arbitrate? Yes, it's an option in other cases.