It seems the more radical nature of a sports city shows even here in post where that cities fan needs to lessen to demean, or try to bring down the other city to some of their levels. In the stereotype that city evolved over the decades seen as radical and fanatic in trite and still is seen in degrees today.
When the history of a city has even cars parked at their stadiums that dared to have opposing team colors damaged even severely. Just in the parking lot. It certainly was radical. At least them days are probably over. But reading posters claim if someone lived by them in that city and dared to display other team colors and emblems on there home? Being a target yet today.
That perpetuates the old stereotype still today there.
But on topic. I think one city did have (debatable yes) eras a sports team had a period of being a "America's team". The Chicago Bear's Walter Payton and Da Refrigerator Perry era had a fairly short run in the early and mid-eighties. But very significant Nationally. There was the more recent Michael Jordon era for another city team and of course .... the Cubs 2016 win and near-win season.
Also having Wrigley Field historic ballpark that is even a tourist attraction for the city. That enhances the BETTER aspect of sports and fans and that city's sports recognition. Opposing team fans still filter into the many bars around Wrigley also with no fear. For football - Soldier Field .... though a newer stadium was built inside aspects of the original stadium still seen on its exterior. But it did loose its landmark status in that change. It still holds its dedication to our Soldiers and not a namesake sold to Corporate sponsorship.
Then you have the pretty long run of the Patriots winning nature for Boston and its historic Fenway ballpark that clearly have significance also.
Another long winning streak city is not mentioned here .... being Pittsburgh for the Steelers also. By me living in the eastern central half of PA. Pittsburgh sports fans still share a good % of the share along with Philly's and even some for NYC's. No problems flying different team colors here or on vehicles. Though bars and clubs generally avoid promoting one team splashed around. Sports bars clearly will recognize both PA's largest cities teams.
I'd say the poll results here is right. Not in one city's favors by any landslides.