Today I wrote on Twitter that passive aggression is underrated. I was mostly kidding/being contrary for the sake of it, but I think that's one of the best ways to find out what you think -- just say something, figure out if you mean it or not later. Seriously, everyone else is doing it.
It's not that I think being passive-aggressive is an attractive quality. As @marstall responded, "civil + direct" is best. I agree. But it doesn't always work. Sometimes when you've tried directness and then active aggression and not gotten the desired response, passive aggression, as a last resort, totally works. And as Gillian noted, there are situations in which other strategies will get you reprimanded or fired.
This came up recently when I described a friend as "maybe a touch passive-aggressive sometimes" (when asked, based on her sign, if she's vindictive). I didn't think this was a mean or insulting thing to say (I can certainly be passive-aggressive at times, though I think I only do it in the comfort of my own home), but I guess a lot of people put passive-aggressive at the top of their Shittiest Traits list. I think vindictive is way worse. Manipulative sucks, but there are worse ways to be manipulative -- passive aggression is generally so transparent, the most I can do is roll my eyes. I'd also choose passive aggression over overt anger and a lousy temper.
So my point is not exactly that it's underrated, more that it's panned disproportionately. Let's pick some other mildly annoying trait to blow up like it's on par with "given to fits of rage." How about "has a catchphrase"? Or "sends 'I miss you, what's up, we haven't talked in so long!!!' emails and then never responds to your response."