I am 45, so I understand what you are talking about. The issue is not strictly age. One does not simply age out of video games. I think the issue is just that our particular age group and generation is sort of on the dividing line between two extremes. On one extreme are those that are older than us have never played video games because they didn't exist when they were kids. My older sister is just old enough that she never played video games because as they were created, they were created for kids my age and younger and therefore she had no interest. To her, they will always be kid things even though they are now developed to be appealing for all ages. On the other extreme are those a lot younger than us where basically everyone plays video games. Not very many of the younger generation gives up entirely on video games.
I predict that in 30 years, video games will be popular in nursing homes and retirement homes whereas currently, no one in that age group has much interest at all. By that time, the whole population will have been exposed to video games their whole life and that will make all the difference.
In the current oldest generation there is not much stigma to deal with because none of them had video games growing up, so there is very little interest. And in the youngest generation, there is very little stigma because everyone plays video games. Meanwhile, we will always be part of the generation where only some of us kids played video games - mostly boys, and mostly seen as the nerds if we stuck with it.