This probably goes both ways. I guess there is people who are actively playing WT or IL2, and have downloaded and installed AH, but cannot find the time to configure and/or try.
The difference to your case is, that if they find the time (or free up their time for that, having "no time" but playing is just making up excuses) to try AH they are looking $15/month compared to $0 currently. In your case, you already paid, and it doesn't matter for them if you try it or not. But even with a potential reduction of monthly cost you choose to not free up sufficient time to even try.
There's quite some inertia. Seems like peoples comfort zones is with exactly the configuration and flight-models they are used to. Any change would mean an immediate reduction of skill level, with new learning required. Probably one of the reasons why there's still as many players as there are.
Understanding why there's still players left might help to understand how have we lost so many people to this wonderful game (hey, that's right there in the subject) and then maybe why there are no new ones.
- no motivation to re-learn flying (see above): prevents new players from other sims
- want to complete the collect-25k-perks achievement: not interesting for someone who never played here (I guess no-one ever said "ok, let's start playing word of warcraft to complete all achievements", that works by becoming addicted first and then choosing the most time-consuming goal available)
- married to the community: prevents new players (married to their current communities)
- scenarios / special events: not really motivating much for new players, because not much can be experienced during the two free weeks; also, aren't their kind of game rounds in the other games, which are basically little scenarios, minus human interaction and flying around for an hour to maybe end up in a fight?)
- prefer the open-world war aspect of the main arena: the only thing where AH is really different?
Anything missing?
I play games I like and don't play games I don't like. It is as simple as that for me being just a player the developers can figure out the rest. I haven't tried IL-2 yet, just because I picked it up a couple days ago and hadn't had a large enough window of sober free time to dive into figuring out the controls. I have lots of games, AH included, that I wish I had more time play and don't find any real need to be married to just one of them. But AH is definitely the only game that ever held my attention for the years that it has/had. AH firing on all cylinders, in my opinion, is the best PC game I have ever played. It just unfortunately hasn't been firing on all cylinders very often these days to really draw me in.
Players speculating why people are leaving or promoting game changes beyond a mere suggestion in the wishlist forum is a complete waste of time. The best place for players to have an impact is within the game itself. Promote a fight, a base capture, a squad, a mission, the history, etc... Promote it to bring in the GV guys, the bomber guys, the fighter guys. When that all clicks AH really shines above them all. It also helps develop a sense of community which has the sticking power. I know it is not easy, I have tried it. You get a lot of flak from your own country men, but it does work. And always funny to see the guys giving me a hard time when I try to get a fight started end up in the fight I was pushing for.