The deal Akon reached with the super happies is so preposterously one-sided it is no surprise at all the babyeaters did not agree to it- and that could have been foreseen. For either humans or the babyeaters to even consider destroying their identity so the super happies will make art and jokes is absurd. For people, at least, self-identity is vastly more important then overall utility. Super happy art and jokes are worth basically nothing to the babyeaters and humans. If the super happies want humans to switch off physical pain, embarrassment etc. they should agree to 1. unconditional sharing of every technological advancement they make, 2. allow the individual adult humans the option of turning pain etc. back on, 3. do our baby eating for us. But thats just a suggestion- the main problem is that the chances of the super happies nailing the fairest possible deal on their first guess is astoundingly unlikely. Even with complete knowledge of human and babyeater culture their knowledge is phenomenologically inadequate for coming up with a deal that is actually fair to all. Not negotiating was irrational, as was failing to contact the babyeaters to get their thoughts on the deal before agreeing to it- three-party deals require three-party negotiations.
That the Confessor didn't step in sooner... is kind of ruining the story for me. I'm not sure if these issues were brushed aside to make your point or if you really don't understand how absurd this deal is.