True, games are not as mainstream as movies. That is due to the fact that it is very difficult for older generations to get "into" games. And yes, most gamers tend to be male and either still in highschool or studying, and single to boot, which gives them more free time than people with full time jobs and families. So games might never be fully mainstream.
But it is heading that way, and heading that way fast. You say the movie industry, combined with DVD sales, makes 10 Billion dollars more than the video game industry. Considering how much the movie industry makes, and how long it has been around and how entrenched in modern culture it is, I'd say that the videogames industry can feel pretty damn proud of itself, especially since most of it's growth has been relatively recent.
And again, you have to take into account which nations you are talking about. In japan and korea, gaming is definitely mainstream. In Korea, they broadcast Starcraft matches on TV, hold huge tournaments worth a lot of money, and even the South Korean Airforce has a star-craft playing team. In Japan, they have a weekly pokemon show! A Show about a SPECIFIC videogame, not just about video games in general! Do you know how insane that is!? And movies have a much larger global audience than games. Citizens in poorer nations often can't afford consoles, but can watch bootlegged movies. So to compare the two industries side-by-side is not giving an accurate picture.
My supervisor for my lab project played videogames. Let me say that again - a holder of a Doctorate in Molecular Biology walked into the student office one day and elaborated at length on playing his PS3. Yes, that happened. He was the best damn lab project supervisor ever. The Ph.D students in his lab played videogames. Pretty much almost every male under 30 that I have met plays videogames (and no, I do not run with video-game playing crowds. I run with no crowds at all, since I am socially crippled).
I think you are having a bit of a negative reaction to the increasing mainstream appeal of videogames. You almost want it to be a niche club. Sorry, but that's how your article comes across. Sure old people don't understand videogames. They never will. But you know what? Old people DIE! OF OLD AGE! IT HAPPENS! And once that generation dies, the only generations left will be the video-game players.