It's not that simple. Depending on the culture, interacting with people of drastically different ages can be uncomfortable for all involved. If you add the general lack of soft skills among programmers, it's easy to see why someone would prefer a "safer" group that's closer to their age over the more general community.

Let those people have their groups, fine. But there's no rule saying you have to cater to them. There's all kinds of people including people who enjoy going out of their comfort zone and experiencing "danger."