We have in the past when it was unexpected during the week or caused an issue with missing something like an event ending or what not. Not many times over extended time for maintenance.
A better question is after years of WoW, mmorpgs and now just games in general how are people still complaining about this?
Go do something else. And yes I get there are times when this is the only time you can play. That sucks and I feel for you but it happens and making a thread asking for at best a days playtime added to your account is probably not worth your time.