Minority opinion here, but I don't find it too hard to believe the Spirits wanted Viper blood bad and wanted it enough to go in as hard as they did on the Viper Annihilation. The Vipers were absolutely dezgra on Tokasha, killed three Spirit Galaxies and Khan Troy Boques there, and killed them ugly. The Spirits have always been passionate and vengeful, and I'm sure the thought the other Clans might wipe the Vipers out before the Spirits could exact some measure of revenge was unacceptable.
And yet the Spirits specifically opposed the measure put forth by the Adders to open up the Annihilation to all of the Clans. If they really felt that strongly about it, I doubt they'd have voted that way. I agree with the sentiment in theory, but the writing just isn't there to support it.
Of all the rotten things Brett Andrews did, the two worst things were the titular Reavings themselves and what he did on Tokasha.
Gotta disagree with this assessment. Tokasha was pretty awful for the Spirits, but the Vipers did more or less conduct themselves under zellbrigen (despite breaking it at the first opportunity, but that's hardly unusual for most Clans), even if they were a-holes about it because, well, they're the Vipers.
It would have been a glorious battle - and the Bloody IlKhan knew it and didn’t want that at all. It would have put the Adders squarely ahead of the Vipers in raw strength.
That theory would have a lot more weight if Brett Andrews didn't immediately turn around and throw damn near his entire touman at the Coyotes in open battle. Plus the fact that the Vipers had already proven in spades that they had no problem facing other Clans with strict honor rules in place and kicking their asses (just ask the Falcons). Plus the fact that the Adders were
already well ahead of the Vipers in strength, and always had been.