This is indeed a very silly situation that we are all in. Everyone has their own preference(s) and due to the wide variety of apps available have come accoustumed to different tools. Every individual uses whatever he or her thinks is the best and most comfortable instant messaging and post-email tool for him or her.
New software with promises of "revolutionizing communication" keep steadily crawling out. It has to stop! There are already too many tools which do the same thing! Software developers are trying to re-invent the wheel, but instead they've been caught in a never ending dead circle... or ring of fire...and it burns-burns-burns.
At first glance a universal tool that would tie it all together sounds very promising, but I'm not 100% sure that it's the final solution. It's another piece of software that might or might not work. For example it might handle Facebook and Google Hangout very well, but doesn't support Skype, Twitter etc. So you'll probably need multiple universal tools for all the services and then you need a master universal tool to tie all the other universal tools together...
In my opinion big players should really get a grip on this situation. Why for example can't Google Hangouts be the base of operations? Or Outlook? Or Facebook? Twitter? Whatever environment is most comfortable for the end user. Make currently popular services more capable so they can easily connect to each other and communicate. If we approach it this way we don't have to worry about migrating users from one service to another, because that can be very hard if not impossible. As I said previously, everyone has their own preferences and opinions... Let them continue using their chosen software / services but add the extra option to connect to other services too!
We are on our way to augmented reality but we haven't figured out how to make text based communication over multiple platforms and services comfortable for everyone... peculiar!
I'm not familiar with all the services that have been mentioned above. Therefor I'm not aware of their exact capabilites and/or limitations. But I want to point out that Outlook IM feature does connect to both Skype and Facebook. It's not perfect, but it's moving in the right direction.