I wasn't blaming big dogs for being big; I was blaming owners for having them out unleashed in an urban environment, in defiance of local law, common courtesy, and (as some have pointed out) the dog's own safety.
I don't go to dog parks. I just looked it up, and it turns out there is one within walking distance for me, but I see no need for it. I have a communal backyard I share with four other dog owners, a neighborhood park two doors down from me that I share with even more dog owners (that's where we ran into the French bulldog), and a large city park four blocks away where lots of dogs are getting walked all the time. When these dogs are on leashes, as they should be, I don't have to pick my chi up, and can let her "meet" them if that's how the interaction plays out. When they aren't on leashes, and aren't responsive immediately or at all to their owners' commands, that's when I have a real problem.