They do play when given the opportunity, but they have different tastes and interests from the rest of the market.

The argument is they are played by younger people because they are designed for younger people. Older people, the ones coming into retirement age, grew up playing video games. They enjoy and value video games, but have slower reflexes and less time. Retirement solves the latter issue. From the article (emphasis mine):

“Developers have been ignoring older gamers for the same reason it took them decades to discover women,” he says. "The industry has spent 40 years chasing the same narrowly defined audience because it was the safest bet, until everyone was chasing it. Imagine if Hollywood only made movies for 18-year-old men. That’s roughly the bet games have been making.

"The opportunity is substantial. The 40+ segment in the US is on track to grow from $19 billion in 2022 to $43 billion by 2030, a 132% expansion at a moment when the rest of the industry is shrinking. These are players with the most disposable income, the longest gaming literacy, and the highest brand loyalty. They are also the least visible in the industry’s dashboards because the metrics were built around younger players who compete frequently. Older lifelong gamers don’t, but they keep playing, and they keep spending.

“What needs to change is the industry’s mindset. An entire generation has now grown up playing video games and is ageing into a life stage where they have time, money, and the desire to keep playing. The first publishers to actually see this player will capture a structural advantage. The rest will arrive 10 years late, exactly like they did with women.”