I can give you a ton of reasons this happens. For me personally I at one time had too many games. This left some games not even being played once a week. After scaling back to half what I had they get played more but still sometimes I can go days without playing. A laundry list of reasons from work, family and dogs. I still consider myself a pinhead but not as hardcore as most.
X-men, LOTR, WH20,TSPP,Family Guy all came and went with less then a 100 plays, no resets, new code ECT. Just played as much as time allowed and wish I could have gotten more of my monies worth.
With that said I just broke a whopping 300 plays on Ac/Dc after two years, and Tron has close to the same amount of play.
Happy to have cool pinsiders over to increase these numbers so it's not as if I am hoarding "my precious".