discussion has proved that most people DON'T practice what they preach.

You are basically saying that I can preach / guide using refrences from a holy book, but I am not obliged to follow the same, because its between me and my Lord.

Abu American can swear and cuss as much as he likes, but can tell others to follow the teachings of the prophet. (who by all accounts was a pious man and would never even dream of getting angry, let alone swearing at another human)

And then you wonder why people get cynical about Islam :)