Microsoft couldn't make a decent chat app if they bought it for $8.5 billion and it was already working perfectly. The only reason Slack came about in the first place is that they screwed up Skype *and* Yammer *and* Lync.
No-one wants to "be a grown-up" either - if they did, HipChat would have won over Slack. In fact Slack's biggest threat is from the other side - Discord offers a better package for free.
Biting the hand that feeds IT
