Last call is at 2 on weeknights.
Honestly, we're spoiled with concerts ending as early as they do in DC. In every other city I know of, shows letting out before 12:00 are the exception, not the rule. Be grateful that we only have to encounter this a few shows a year. Just ask anyone from the Baltimore area what the average end time for a show is. If you get the occasional show that ends late, either suck it up or stay home.
Sounds as though those who sucked it up in this case are happy they did.