Worth noting Cap never actually displayed a willingness to work with the villains, at last not in the first take. He doesn't get a chance, since Frank blasts them as soon as they're done talking, when Cap is still surprised they'd even show.

And I don't buy that SHRA would affect the villains more than the heroes, since a lot of them live as fugitives anyway if they're not in prison. Reformed supervillains, sure, but active ones?