Balance/imbalance is not what i was talking about. While i am happy that you agree with almost everything i have to insist that it is overused.
First of all by definition "overpowered" describes something that is extrordinary powerful, a one in a million thing. Like Messi, he could be called overpowered because he can always kill any defense, no matter how good they are. Or like camels. Against a unit like that there is often no defense, no matter how skilled the defender is. If now most teams had a messi or most civs had a camel unit they would no longer be overpowered and instead be one amongst many. Like Poland, one of the very strong civs, but not overpowered as op claims.
Second i find it overused because it is so often just regurgitaded (Wow, i just had to look up "nachplappern" and was surprised to find an english word for that
) People pick it up, like the expert sound of it and then cant stop using it. Uncountable games have been lost because the other guys' civ was "overpowered". But also experts are guilty of overusing it imo. Watch a random multiplayer video by one of the big guys and i guarantee there will be overpowered stuff left and right.
I dont know how the public sees the game. I always thought it was intentionally created in an unbalanced matter to reflect some specific strengths certain civilizations had. When 2000 years ago the roman legions marched through the known world and set up their ballistas, man, these guys were indeed overpowered compared to everything else out there. In the game, btw, they are not, just two very strong early units.
The imbalance seems to be a big topic in the community since more and more players wanna ban/draft before the game starts. Im usually "-" to that because i like the imbalance. Its nice to be england once in while, and also the challenge to have to deal with them is enjoyable.
While i am at it, but this is more and more getting offtopic, in a concrete game it may often be a significant disadvantage to play one of the truly overpowered civs, because you immediately become the target.