When people say, "my team," they mean it.
In the top-down world of industrial marketing, the San Francisco 49ers say, "we built this team, buy a ticket if you want to come."
Then, a few years later, it broadened to, "you should buy a jersey so you can be part of it."
In the sideways, modern world of peer-to-peer connection, people say, "my team has this player, that player and this defense." It belongs to them, because they built it. Everyone has their own team.
In neither case is the fan on the field, getting concussed or making the big decisions. It doesn't matter. What matters is that our feeling of ownership, of us-ness, is shifting. We want celebrities and brands and teams that do more than merely put on a show. In addition to the show, people want to believe that they own part of it.