To be fair you can do this on Twitter too. If you follow someone's public Twitter list, you see everything from the people in that list. And (unlike Google+, I think
-- I hope I am wrong), the Twitter list is dynamic. So if you followed my IPG list (at https://twitter.com/#!/estherschindler/internet-press-guild
) you'd see post from all those journalists; if I add another person to the list, your feed gets that new addition, too.
The difference is that the Twitter lists don't appear in your timeline; you have to look at them specifically. Which can be an advantage. I have a Tweetdeck column set up to follow one friend's Twitter list, so I can "pop in" and see what that gang is up to.