This is a really odd sentence in English. Is this more of a non-literal translation of chivalry is dead?
I don't see anything odd about it. If someone was rude in public this would make sense to say.
That would better translate to "Η ευγένεια δεν είναι εκεί" In Greek, something is not there (κάτι δεν είναι εκεί) doesn't mean something doesn't exist(κάτι δεν υπάρχει). Or at least I haven't heard it before or seen it in texts somewhere, as a native Greek speaker. ^.^
That is logically so correct! "Something is not there" may at the very best insinuate "something does not appear/is not known to exist", but this is too inconclusive to deny the existence of something. No wonder Greece has produced so many philosophers :-)
Manners are τρόποι in greek. You have no manners!=Δεν έχεις τρόπους! His manners are awful=Οι τρόποι του είναι απαίσιοι.
Personally, I think friendliness would be a better translation for φιλικότητα, rather than ευγένεια. ^.^
Politeness is not used that way. We can use "politeness" in these ways...e.g. from Oxford "he always treated me with the utmost politeness"
Cambridge "politeness is about respecting othere...."
English uses a lot of fixed expressions which you'll get used to over time. Start by learning the way things are used in the course. Use the Drop down hints to find meanings.