Because we can't afford to lose any more players. Also having people use nazi-like (report and deport) methods ingame is equally lame.
No one gets banned for being AFK though...so your entire post is pretty much gargabe.
Why should COH2 be a lawless place where everyone can just insult others without consequence??
It creates a toxic atmosphere where you can get rid of unwanted players and sometimes don't know whether you are allowed to say certain things: Is an "early gg" a reason to ban, a "Shut up?", a "l2p"-message?
And then this is all put into someones hands to decide. Those people paid money for the game.
You never know when someone is going to be offended. For example your avatar shows a murderer. How would you feel like if I was able to report you for that just because I'm an offended snowflake?