So people that steal boats and holy gems are somehow not "sneaky" or "duplicitous"? Didn't they ostracize ex-captives of Morgoth/Sauron? What about Maeglin who turned traitor in exchange for his crush as a "spoil of war"?
It is quite clear that Elves are capable of doing "bad" things for lack of a better all encompassing term and it has nothing to do with "modern politics" or "bubbled societies".