Huh, this chapter has some of the things that make me remember this manga has a weak plot.
Because, the more I think about it, the less likely it seems truly all gods would agree with this whole tournament and killing all humans if the godly side wins.
Susanoo definitely seems the type to appreciate what humans can create and respect them too much to just want them all dead...
He could also be participating just to fight strong enemies without thinking on the consequences like the dumbas Super-version of Goku.
But we already had Hercules and Buddah with the same thinking that humans are too worthy to kill them.
And by his comment chapters ago, Thor seemed ambivalent respecting strenght over everything.