Your reasoning for capping team size is valid, how is linked to WWDC ? "Easily tripling" the attendee size would make the sessions, usually given by Apple engineers on the team, into unsupportable mobs. Lot of the sessions are full to begin with. The theory also doesn't hold up when looking at Google. Google, who could easily argue has the opposite philosophy on focused development and community inclusiveness, caps Google IO held in the same building as WWDC, at 5500.