'Feed reading is an open web problem'

Luis Villa raises an excellent question about RSS being an open web problem:

In other words – why is RSS an open web problem? why is it different from, say, email?

His answer:

If my browser doesn’t tightly integrate email, the open web doesn’t suffer. If my browser doesn’t tightly integrate feed discovery and subscription, well, we get exactly what is happening: a mass migration away from consuming (and publishing!) news through the open web, and instead it being channeled into closed, integrated publishing and subscribing stacks like FB and Twitter that give users a good subscribing and reading experience.

And then he explores what is needed (by browsers) to fix this open web problem.