It's not a good business model to make everything right away
Look what happened to air warrior and fighter ace
They had every axis-allied planeset
where are they now?
and From what I understand is that the games I mentioned had no more room to grow. Air warrior for example had every plane from ww1 to korea.
we can just keep dreaming about new planes because I think it's of HTC's interest to slow the growth/progression of planes here. At the same time I think HTC's gotta be manuverable and keep up to date on demographic and consumer trends