I personally do encounter a lot of this kind of thing in SF, except usually just in latin shops/restaurants. And instead of candy, it's some nick-nacks (usually along the lines of childrens clothing, rosary beads, virgin mary pendants, etc), being sold by an elderly person.

I never really buy anything from them (though my mom sometimes does), and even though I do prefer my meals to be uninterrupted, I would never say they annoy me, or that they shouldn't be doing it. Life can be hard, and you can tell these people are genuinely trying to make the best of it, so I truly respect them for it. If anything, accusing them of 'violating' anything when they're working so hard, doing something so simple and innocent, would just make me feel like less of a human being.