To me, a chassid is something in the heart and soul. I really don’t know what the “lange rekel” has to do with it. I guess you are signifying to others that you ascribe to the philosophy?
Or, one element of chassidus is the “am hashem”. Chassidus attempts to make jews into a distinct nation, with a distinct language, and mode of dress. Therefore they wear the “lange rekel”. They don’t seem to care to much about a distinct land though, generally speaking.
Whatever the case, i still beleive that chassidus is a philosophy, and a way of life. I don’t attach much importance to the “levush”, but its a nice detail, IMO.