It's not that it's too hard, it's just not something I want to worry about. I think some people like to really organize things and some see it as a hassle.
For myself my inbox has essentially two folders. Inbox and Archived. My facebook lists is just friends and my google plus circles is just whatever the default is.
I don't want to think about who I'm sharing things with. I either share it with everyone on a social network or send it as an email to specific people.