That's the point: it's very difficult to automatically determine what someone wants when they follow a project. Sometimes I only want to bookmark it because I know I'll find it useful in the future. Other times, I only care when a new stable version of it is released, with a changelog. When I'm a participant I want to see more details, like new issues or commits.

Instead, because of the lack of options, we're left with an unusable wall of notifications. Smaller projects get drowned out by larger ones, and it tells me every little detail of what is going on with every single project. I'm pretty sure I've never clicked on a single link from it in the past few years of using GitHub.