I'd like to add a few reasons why the WW2 players in particular might enjoy spending time in there occassionally

11. You know how the German pilots in WW2 generally had the edge on Allied pilots when war commenced? It was largely because of their early experience flying gliders (Germany was initially banned from training pilots for the military after WW1, so they embarked on a 'civilian' flying program using gliding clubs to get them up to speed. Turns out that learning the basics this way is a good idea.) I think maybe the a/c in the WW1 arena might serve in a similar way; a great introduction for beginners and something different and simple for the experienced. A cleansing, so to speak, allowing the simplicity to wash away the cobwebs of detail and complexity and reveal the pure essence of the business.
12. ... and if there's nothing new to learn in there then you should clean up
13. The history! An earlier chapter in the great story that is aviation. All these gaming experiences are better if you get your head into them. Personally I fly each sortie in an old leather flying cap and goggles, silk scarf and Snoopy motif underwear (although I had to get ADSL at home, the manager of the internet cafe called the police). Soak it up!
14. And finally, how often do you laugh - actual fits of mirth - when you get nailed in the WW2 arenas? This is like being in a cartoon, c'mon... remember that movie, 'Those Maginficent Men in their Flying Machines'?.... you dive on the Red Baron, he's at your mercy... just a little more back-stick, you start to grey out.... and
crack the wings come off and you sit there in your wicker basket seat giving the stick a futile wiggle or two as the remnants of the ridiculous contraption plummets to the ground, the torn appendages mocking you as they flutter slowly earthward in your wake.
15. Great company. Very few take it too seriously, and if they do it only makes it funnier when their wings come off.