that article doesn't give a complete picture. world of warcraft player attrition numbers are a reflection of the pc gaming market in general, not to mention the lack of fresh content. wow and games like it, has a double whammy, you have to pay for the base game, and the expansions, then pay a subscription fee. the article doesn't even look at the decreasing average age of online gamers. the free to play/microtransaction market has become more and more popular due in large part to the economy, new mmo games being released and the number of younger players who can't afford to pay monthly subscription fees. as long as the developers keep the content fresh and maintain minimal maintenance down times, they will keep a large part of their player base. if they let a game get stale and don't improve it, they won't last long. most of the f2p mmo games are generally considered "pay to win" games and in the case of swtor (as well as other similar games), if it's a point and click grinder, a subscription model isn't going to work well for long. the gaming market in general, especially the mmo genre is constantly fluctuating with players grinding through the games and jumping from one to the other.
it wouldn't be real difficult to track a players online time in aces high but, imagine the angst that would be caused by getting disconnected when the player surpasses the time they have paid for. especially if they are using a perk plane/gv at the time it happens. then to add to the frustration they have to go dig out a credit card, try to figure out how much time they want to pay for, and get back in the game. the entire structure of ah doesn't lend itself to a microtransaction system very well. if it were more like the latest entries in the war game mmo's, (warthunder, world of tanks, world of planes, etc...) with limited player options from the start and fast limited action options, then a microtranaction system would work. then again, would the game be as good and how many existing long time dedicated players would be lost?