If you compare it to speed of adoption of WebSockets, variety of WebSockets implementations and how much it is used commercially.
There are many conversations by many developers who as well attempted using WebRTC for server-client communications, and it is apparent trend.
One of the developers of WebRTC team at Google who worked on DataChannel and network code admits himself that their team is aware of complexity and difficulties with WebRTC in server-client cases: https://news.ycombinator.com/item?id=13266874