Well, I know from their direct statements that a number of my ex-squad mates (and a notable nemesis or two) left because of the new version not agreeing with their hardware--and their own set-in-stone ways. AH3 is a much better game overall, but people do not enjoy upgrading their computers. These people may not be a majority, but they exist.
I simply went and got a better video card. It wound up being a real bear to get the skin viewer to work with it. I still don't know what I changed to finally fix that issue. But it works now so I'm not changing anything. Lol
I also no longer play and numbers are the reason. I keep my sub and still work on skins, but my time flying is zero. I intend to see about changing that soon. If people can make their presence known then they might intice others to stick around.