Communication: Steam

Hi, First post. I really just wanted to make a discussion about the importance of communication after a particular game i just had. In this instance i was on a 3v3, and my flank player just started mining my gold. I kept asking why he was doing this, as his base was completely untouched. I said i don't mind him doing it if he gives me a reason why, but it probably would've been better communicating to a brick wall. Fast forward to the end of the game i'm trapped in a 2v1, and he's still mining all my gold, not helping and nor communicating. Long story short, what's everyones opinion on team communication, should there be more emphasis on the importance of it on such platforms as steam?