"Tact is just not saying true stuff" as summing up Cordelia's attitude to life...

Yeeees. While ignoring the thing she was talking about when she said that? Wasn't true at all.

That seems to be par of the course when it comes to snarky, "jerk" characters. Whenever they say something, people just take it as straight talk because they're rude about it. The do the same things with Spike and Anya. It's like an inside joke fans refuse to see. Spike tells Buffy she doesn't know what she wants, yet he's the one who spent the entire episode telling her to leave him alone while following her and waffles between killing and saving her.