I guess it’s a good thing I’m not a cop. For many reasons, including the fact that I don’t have the right temperament, and would have a hard time being patient with people, but if someone refuses to show me an ID, I would instantly become suspicious of that person.
So I’m guessing that that wouldn’t be considered ‘reasonable cause’ for suspicion.
Taking it another step further - if you don't let the police come into your house and search it - if you have nothing to hide, then you wouldn't have a problem with that.
Refusing to let your house, car or person be searched is cause for suspicion, and requires the cop to take action.