Sarcasm is an adjusted stress reaction.

I found the idea of everyone suiciding out of despair both unconvincing and unhelpful. Surely at least a few would take the eat drink and be merry approach? My first thought when they said "suffering is information," was that people were killing themselves in order to avoid giving any more information to the invaders, a much more compelling and uplifting reason.

I think your idea is even more likely, but I guess didn't fit so well with the rest of the plot.