I had two big concerns about this video, but creating a bad rap for "pit bulls" (although I recognize that this dog is not an APBT or an am staffy) was far from one of them.
My first concern is that I don't know anything about this man and whether his "service dog" is actually a service dog or if it is just a dog that he got certified as a service dog to prove a point to the public.
My second peeve was that he spelled "too" incorrectly.
That said, looking at the larger picture - I don't see how having a well behaved pit bull looking dog in public is going to hurt the breed's image as a whole. Rather, I would imagine that people who might otherwise assume that all pit bulls (I'm lumping bully types into a single category) are "man eaters" would actually have their views swayed for the better by seeing a well-behaved pittie type dog in public.
Please don't get me wrong. I am not condoning getting a service dog title for a pet dog just to be able to take it into public. Nor am I putting in a plug for American Bullies (or whatever this behemoth of a dog is). I just didn't get any inkling from this video of "OMG he's perpetuating the negative stereotype of the breed." If anything, it seemed to be the opposite.
Shoot me down if you will, but I wanted to chime in before my first impressions got tainted with the views of other posters.
ETA - I did see quite a bit of arrogance on the part of the video maker that also bothered me, but I figure that that is beside the overall point.