I mean, you are level ten, some people aren't really that quick to learn how to use ping and such. And later on, if premades play, they are probably communicating outside with each other, but never actually say anything or ping in game, and while that might not be great teamwork, it's not really bannable in my opinion.
And then there are people who might go with team, do everything but never actually ping or say anything, what do you do then? If a person gets salty about a few mistakes and exploits this for a easy punishment against someone innocent, what then?
In the end the utter lack of communication is rare. Even then just report for unsportman. Since communication is such a fluid part of the game, you really will have a hard time to determine what should be banned and what shouldn't. And honestly, if my team is losing badly, and can't teamfight, and I choose to mute them, not speak to them and just try to split push or farm, they shouldn't be able to report me and get me banned.
Also, again, I would like to mention that more than anything it sounds like your support and jungle were assholes who simply wanted someone to blame and Ashe happened to do something that made her a target. Yes, Ashe isn't doing the right thing by not grouping, (though I can't really fault the smite, considering both your level and her possible ignorance on the meta) that doesn't give any right to support and jungle to behave as they did. That's their fault, not Ashe's.