The movies could use more bad gals these days, more “Ask me if I care?” dames like Peggy Cummins’ sharpshooter vixen in Gun Crazy, Annie Parillaud’s assassin savant in La Femme Nikita, Rebecca Romijn’s slinky-chic manipulator in Femme Fatale. But if we’re not careful what we wish for, we’ll only get more characters like the one Rosamund Pike plays in writer-director J Blakeson’s wanly nihilistic I Care a Lot, a grifter who positions herself as a guardian of the helpless elderly so she can bilk them out of their savings.