As time goes on the non-gamer generations die off. The gamers grow richer and their willingness to pay increase. The new generations will probably also game.
It's still fun, you just don't have the time anymore (I feel really bad if I take out a 3-hour chunk of time to play a game, or a real-time game which demands 1-hour of continuous focus).
Much as I don't play football anymore but still watch it, I also follow some games :) and so do many friends in their late 30s / 40s with families (mostly the same ones as others in the thread, like Magic: The Gathering, League of Legends, Hearthstone, etc.).
They grow out of playing video games perhaps, but there's a whole world of content for folks who still like video games but don't play them as much anymore.
The question isn't whether people will game - the question is whether eSports will continue to grow as it does now. Being a gamer and being into eSports aren't one and the same. I play a lot of games, I don't watch a lot of eSports (it doesn't interest me).
Not that I'm saying the market won't grow - on the contrary, I think it will continue to do so. It's a very small market compared to sports generally ($1 billion would barely buy you a top class sports team, let alone a network like ESPN).
I don't watch sports and I don't watch gaming streams either. But I think it's an interesting phenomenon so I've asked my friends that do why they do it. It seems to be a mix of excitement about what is going to happen and wanting to learn the tricks of the pros.
People generally seem like watching sports/esports they themself participate in.
I don't see these trends disappearing or diminishing.
