Many new technologies take an old way of doing things and simply change the medium, without changing the fundamental way it is done. Email is one of those things. It is in the name - it took mail and made it electronic.
Anyone who uses email at work (i.e. everyone) will know how frustrating it can be. If you are cc'ed, should you bother to read it? Some people use it like twitter, and only read the first few lines and respond. Others take their time, think about a considered response, compose it carefully and then send it. You can't edit an email that has been sent. You can't recall one sent by error, etc. etc.
Email only works for 1-1 tick tock conversations. I say something, you say something etc.
Outlook is behind at the moment in terms of social media and it is evolving so workplaces are perhaps less keen to try it out unless they are small and used to/driven by change.
But I think in a few years time we will start being able to use a new rule...
Only send an email if there is only one person involved. Otherwise start a conversation.