Post-Celtics rush

Went to the Celtics game last night and took the Green Line home.  So here's what I don't understand: There are 20,000 people heading out of the Boston Garden and it seems like half of them are taking the T.  So why aren't there trains waiting for us?  Seriously, not that hard.  Have a couple of trains ready to go as soon as the game lets out.  You know it's coming.