Or has a pet. I could see a cat doing that over time, and my recliner in my living room has a similar tear because it's basically my dog's chair/bed, and he does that digging-to-make-the-ground-comfortable thing before he lays down.
Yep, combined with lax seating positions. You press into the back so your ass kinda pushes forward, being stopped by the friction with the chair, which then slowly but steadily wears it down. I change my position fairly frequently too as I can't stand (...) sitting in the same position the whole time.
Especially cheaper chairs will degrade like this very quickly but I've yet to see a chair that not goes through this process (I'm too poor to afford the expensive models though). If you reach the point of having a big hole I'd suggest putting some other fabric beneath it - that at least helps preserve the foam some longer. Also, this faux leather material is very bad with sweat and starts to become stiff quickly, causing it to crack and peel.
Is the roommate male? It kinda looks like the chair has been subject to modifications regarding creating a comfortable hollow for a ballsack along with one for its neighbor.