From all my flights at T2 the departure gates have always being like that. 300 gates are always up so people can't make excuses as to why they missed the flights etc. I havn't noticed that further up Pier E the gates are up but will see next time but they always only put them up 45 mins before departure. Its makes sense in some ways as most gates have limited seating and it stops passengers who are not travling on x flight to be sitting at the gate taken up seats when there is no need. They also do have a large seating area at the top of Pier E so passengers don't have to stay in the shopping area!