Once again, Randy, you were advocating a Rolling Plane Set to force players to fly a particular environment.
That's NOTHING to do with what I'm suggesting. What I'm suggesting is finding what tweaks can be made to the other three arenas to draw people to them.
For example, almost from its inception the same main complaints about the WWI arenas have been made:
1) The Dr.I needs to be perked. BADLY. As I said in the OP, WWI may as well be the Dr.I arena.
2) The plane set in general. We have two British and two German aircraft. Where's the Nieuport and SPAD, both of which were significant aircraft, the latter of which in particular would be a WHOLLY different type of machine in this arena, being a true E-fighter/BnZer.
3) There's really nothing to do in it. People can talk all they want about just wanting to furball, but if that's the case, why don't we see 300+ people in Furball Lake in the Dueling Arena, rather than 300+ in LWMA? That strikes me as confirmation that people are wanting furballs that are DRIVEN by something, which the base capture mechanics provide.
Fix those three issues. Perk the Dr.I; add a German machine or two like one of the earlier Fokker biplanes and an Albatros along with one of the SPADs and Nieuports and maybe an Allied perk machine like the Snipe; add some sort of mechanic to generate fights (balloon busting, some sort of land grab mechanic, strategic targets and bombers, whatever) and you'll almost certainly see more players in WWI.
If fights take too long to get to in EW because of the lower aircraft speeds, allow smaller maps with closer bases. If airfield captures are troublesome because of the size of the towns, come up with a new mechanic (IE maproom right on the airfield itself rather than having to blow up the town).
This isn't about "making" anyone do something they don't want. It's about finding the right sort of cookie to encourage them to give it a try.