It couldn't be more obvious, and I bet he's delighted he got some encouraging comments. Yes, OP, there are uniform fetishists among the Trekkies, and they will defend the legitimacy of their preferences just as strongly as the rest of the dress-up crowd. But at least our confreres don't sew strategic holes into their costumes.
Yes, but they are rebelling against the community by wearing such said costume. No one can identify with their actions except others who do the same thing in other cities across the globe.
As for Trek v. sports, it must be remembered that sports are much more decentralized and democratized. There are local sports teams with a direct effect on the local economy. Watching them, and participating in rivalries, socially binds one to one's neighbors. There is an assumption that one "roots for the home team," and as such, those living within the home team's bailiwick are assumed to be members of the sports fan community. Professional sports are also an amped-up version of the same games that many people played as children or students; watching them at the pro level allows one to appreciate virtuosity in a familiar activity.
Trek is centralized. It all comes from one place. There is no local Trek, it has no effect on the local economy (unless you live in LA or happen to write for/draw royalties from Trek), and there aren't really any competitions to encourage rivalry. There's no public sense of community. Watching Trek doesn't allow one to appreciate a familiar activity performed well, unless one happens to be an actor or a subspace field engineer.
So, I can see why one might wear an outward sign of allegiance to a sports team in public. It's a sign of a community that many people think already exists, and most are willing to accept. There isn't an analogous Star Trek community. Perhaps if Star Trek were democratized--if people could participate in Star Trek as children, grow up to do it professionally, and if every major city had their own Star Trek theater where their own Star Trek team performed--then wearing Star Trek costumes in public might be widely considered normal.
Now lets just say hypothetically speaking that sports was an activity where everyone watched an out of shape man slowly painting the side of a house. What is to be gained from it? Besides hanging out with other people who like to do the same boring thing? If I see that my fellow neighbors love to get into watching that, well, hey, that is cool for them. I find it to be a waste of my time as a group effort. As for the economical benefits. Well, just because something makes money and goes into helping the city doesn't always mean it is a good thing. Guns and drugs can help the economy, too. But we don't push those at neighborly group events. Now, I am not implying that sports is evil or anything. Far from it. It can be a tool used for good. I get that. But in my opinion I think it is a very insignificant activity to watch other people run around throwing a ball when it has no real impact on my life directly (besides some small possible sense of connection with fellow neighbors who like to do the same boring things).
Now, if my community were to walk or climb a mountain for cancer together. That would be different. It is an activity or a cause that is going to keep you in shape and do some good. But drinking and yelling at a TV screen or in a stadium while others do the running around is silly to me.