Well, given that I aced the interview (plenty of evidence besides the job offer I got within 24 hours of it and some of it I probably shouldn't know but I do), I should have been a wonderful fit then, no?

Tell ya what, how about trying one of those infallible(tm) A/B tests where half the incoming people get the Hogwarts hat and the other half get to meet their team upfront before accepting a job? Do this for a year. Now one year after that measure which set of employees is happier/present/more successful.