Just my $.02, but this is the most insightful post here.
The definition of the word gamer in the summary is seriously lacking. There's a big difference between someone who spends fifteen minutes playing Solitaire, or Candy Crush, and someone else who's spending twenty hours a week raiding WoW. That said, for the companies who make the products, it's all about who they can pull the most Benjamins from.
And just back to the definition. I have a mother-in-law, so spends about 30min/week playing Solitare, and aunt who is on Simpsons Tapped Out every other day, and my mom who likes the occasional slot machine. All of these ladies are in their 60-70s, and I'd probably be frowned at if I were to tell them that they were "gamers".