Because #poundfist
Let me explain. As a fairly casual EU player (ex-raider, ex US account holder) who dedicated close to 100 hours tracking timers and camping Poundfist for the mount, I found twitter to be a really REALLY welcome source of information and distraction to stay awake as we were approaching 'that time' we were guesstimating he would pop. EU servers don't get the spreadsheet love US servers do, and it was really cool seeing EU realms post #poundfist selfies and kill confirms on twitter. And I did my bit and posted our realm and time of death and selfie. So I get it. I get that by tabbing out, I was able to stay focused, give our 40 man camp hope and keep them motivated as the EU kill reports started rolling in. Also to prevent future groups on the server from camping wastefully because they now knew exactly when the last kill was.
Today I give Jack his jacket. Well played Blizzard.