You're right though. Computer games is not something you 'grow out of', like many people think.
The reason people think is, because older people these days tend to not play videogames (with a few exceptions always). But the reason they don't play videogames isn't because they 'grew out' of them, but because of the generation gap! They never grew up with videogames, so they never really start playing them. Alot of them don't start because they think it's very complicated, or can't get used to it.
As for the new generation, most of us will grow up with computers and/or consoles in our very homes. This is a major difference ofcourse.
I think that by the year 2050, most gamers will in fact seniors, simply because that generation will understand videogames, like videogames, but ontop of all, have the time to play videogames. (All the time in the world!)
And you know what? I'll be happy when that time comes, because frankly I'm getting tired of 1337 13-year olds ruining perfectly good games like Counter-Strike, or any other multiplayer FPS for that matter...