Not that I have any idea what I am speaking about here....... but here is what I think........
There is a natural progression for players in this as well as any other game. Players go through a natural cycle..... Birth, Life and then finally Death. The time frame for this to take place is different for everyone. I made it around 4-5 years before I finally came to grips with the fact that the game was dead for me. I think the players personality type has alot to do with how long it takes for perminate burn out to take hold. I for one am (at times anyway) wound fairly tight so I didnt last as long as others.......
The point is that the number of players who leave AH is most likley fairly stable. In the 5 years that I have been here I do not recall any mass Exodus.
How many new players come to AH is a reflection on how well HTC promotes thier product.
As to your original comment though I must say that I recently saw something that caught my attention with regards to Aces High. After moving to Falcon 4 from AH I began to read SimHQ forums and articles. For those who dont know about SimHQ you should..... check it out
http://www.simhq.com/ They recently had a "Best of 2005" thingy going (I am to lazy to find the link right now) and they had a "best online gameplay" category. AH didnt even make the list. Hmmmm..... Make your own judgements here.....
FWIW, Falcon4 AF won the flight sim of the year title beating out Lock On FLamming Clifs.
Dave