The first few times these discussions were interesting. But for every submission mentioning Slack, somebody has to come and claim that IRC is all anybody ever needed, and all the arguments have been rehashed over and over. The alternatives mentioned in the article on the other hand are barely discussed at all.

I'm sorry but from where i am it's not "contrary opinions" being downvoted, it's useless dribble.

Hell one of the downvoted comments is just "IRC comes to mind"... Just hand waving away all of the problems that something like slack is trying to solve, which the article talks about.