I think you will find trash talk wherever you go (Grepolis or another game), and the fact of the matter is that most trash talking is not friendly banter. While I am not defending extreme trash talking, or rule breaking, my personal feelings on the subject are as follows:
A trash talkers success relies on how you react to what has been said. We do have a code of conduct and we enforce that everywhere, but things are going to be said that fall within that code of conduct that you or someone else may find offensive.
I see two options, you can let the trash talk affect the game you play, poison your environment, and ultimately send you off the internet/site (which I might add is that trash talkers goal, so by choosing this option you let them win), or you can choose the people you talk to, the posts you read, the threads you open, and the alliance matters you take part in.
We give several options so you don't have to see the trash talk. You can report inappropriate messages, block players that you dont want to hear from, ignore people on the forums. You don't have to interact with everyone.
tl;dr: Trash talk is everywhere on the internet and cannot be avoided. You have the option of exactly how little, or how much power you wish to give trash talkers, but giving them the power to send you off of a game is like holding up a white flag and giving up the fort.
So uh Bayou, giving up your cities are you?