I obviously understand what you're saying but it does lend credibility to a pattern. No matter how you slice it repeat buying its still there and its strong with reoccurring annual titles. Its the deeper more realistic experience that promps the purchase, not casual simplistic one button gaming.
I've met a number of people that have skipped a year here or there but have been a repeat buyer at some point in the game. They're looking for the same kind of experience most of us are. I've never met anyone who just randomly picked up Madden one time looking for that casual one button mashing experience. I do believe EA has come to terms with who their market is.
If I had to take a stab in the dark I think it would look something like this.
10% hardcore sim gamers annual buyers
10% very serious gamers annual buyers
50% semi-repeat buyers looking for a realistic in depth, FUN, gaming experience.
20-30% randoms or rare repeat buyers who don't play their games annually.
...but that 20-30% are still "gamers".
Everyone piled on the "casual" gamer hoopla perpetrated by the developers and their superiors at the beginning of next gen gaming. It was a money grab and a bad business model. They have abandoned that formula recently. The evolution of all gaming has changed.
You can't deny that in the last 3 years all the big sports titles have begun catering to the more demanding audience. Online associations, deeper gaming experiences so on and so forth. There is a reason for that.
What we want to a degree is what their target audience wants. Sans that ultra hardcore upper 10% or so. I buy every year and I don't even put myself in that category.