Corvids and psittacines display human child level intelligence. They use tools. They recognize other people. Hell the psittacines can mimic speech.
I personally suspect it's a matter of energy density. Birds have to use almost all of their available calories on flying. Doesn't leave a lot of energy left over for a massively hungry brain. No clue what's holding back penguins, emus, and cassowaries.
For some reason, I don't entirely believe you. Might be the whole God of Madness thing. You turning back into Jyggalag anytime soon? I'd like to know when to short the shit out of the entire market.