Her cover identity is the creative genius behind a successful tech startup. Being dumb would not serve it. In fact, sadly, being known around the office 110% for her extremely sharp brain would be the best possible way to distance Karen Starr from Power Girl; the superhero is known for her boobs first, for being an unrepentant, very straightforward, physical powerhouse badass second, and for thinking anything through, ever, not at all. (I still grin a mad, broken comic-fan grin every time I remember that they made her JSA chair way back when the title restarted.) If, as we've been repeatedly assured, the thing people notice and remember about her is her cleavage, ought she not be primarily cleavage in both her identities, and instead be body in one and brain in the other? (I'm taking bets now on how long it is before somebody figures out her secret by the shape of her chest, like that first BIRDS story where the girls peg that guy by his distinctive ass.)
Bevlin is clearly going to be her first rogue. Palmiotti and Grey were talking in interviews about how a major goal of theirs is to establish a gallery for her, and that whole scene had "hey, say hello to our nascent supervillian" written all over it. So no way is he a permanent foil for her secret identity, unless he starts up a company of his own.