Honestly, I would say a lot of people that are still subbed, are subbed largely because of friends.

For myself personally, I probably would have gone on a long-term hiatus by now, if not for the fact of friends that I still have that are still playing and progressing. I think when it comes to most things that the developers try, I feel like they are largely creatively bankrupt, and/or directionally/strategically confused. - What I mean by this is from 1 expansion to the next, they don't seem to know what side of the fence they want to go for, or at the very least seem wholly incapable of balancing what they produce with the feedback they receive.

For what it's worth, I don't think there's a care in the world. If there were, they wouldn't need to be asking why peoples' friends are unsubbing or not playing the game.. I say this because if they cared they would have discovered the reason well over 4-5 years ago.