I would blame UX there :) In my mind a collaboration tool should not be a burden, if people let it down, it means it's not appropriate. Hence the success of Slack: people realised collaboration can be made easy and real-time without being a pain.
And wrt self-hosted chat servers, you can have a look at some implementations of Matrix (http://matrix.org): there is an opensource a ref implementation of a server (https://github.com/matrix-org) and then a bunch of clients at different level of glossiness, for web, iOS and Android (http://matrix.org/blog/try-matrix-now/) available. Or you can build your own if you feel like it :) Fully decentralised and persistent communication.
No full blown collaboration tool but public & private chat rooms with the ability to exchange files and do 1:1 voice & video calls (group call is in the pipe).
And wrt self-hosted chat servers, you can have a look at some implementations of Matrix (http://matrix.org): there is an opensource a ref implementation of a server (https://github.com/matrix-org) and then a bunch of clients at different level of glossiness, for web, iOS and Android (http://matrix.org/blog/try-matrix-now/) available. Or you can build your own if you feel like it :) Fully decentralised and persistent communication.
No full blown collaboration tool but public & private chat rooms with the ability to exchange files and do 1:1 voice & video calls (group call is in the pipe).