Was fun for two weeks. Then quickly burned out due to very limited gameplay / combat situations.
Today I would still fly a couple of hours per week... but arena population is often 0, and only occasionally 1-3 guys at my timezone. And I'm not interested in dueling.
If there was a WWI arena with some depth and variety comparable to the MA, I would prefer it over WWII any day of the week.
That's why I never fly there. In the MA there are a million things that can happen, and you never know which you'll be facing. In WW1 there is exactly one thing that can happen: fly to dots on dar, turnfight a while, eventually get killed, rinse, repeat.
It wouldn't have to be strats to bomb or capturable bases (the latter would seem out of place in a WW1 game), but it needs
something to provide focus and variety for the action. Trench strafing, recon, balloon busting, anything so that players have something to do other than flying straight at the enemy and circling each other all day.