Wearing a Star Trek communicator badge at work

I'm a fan of Star Trek, and I want to wear the communicator badge on my uniform when I go to work for BA. Should I be allowed to do so?

BA, it turns out, don't like employees bringing their hobbies into work. However, they ask me to cover up the badge instead of removing it entirely. What logical argument is there against this? That I'm wearing the communicator badge to actively promote Star Trek? If so, it's hardly reasonable to do that on somebody else's time. But maybe it's impolite of them to ask this of me. What harm is the badge doing, after all? Well, it could provoke discussion, which is a waste of company time, something particularly valuable when I work at a check-in desk! It could also cause problems with crazy Babylon 5 fans who think my wearing of the communicator badge is insulting. Yes, they're mental, but it wastes time and money and who needs the hassle? In response I point out that BA is allowing Firefly fans to wear Truly Excellent Hats, on the basis that these can't be covered up. Everybody mumbles incoherently when this point is raised. Nevertheless, I do actually work for BA: they can request anything they like of me, providing it doesn't cause harm to myself or others. If I don't like that they want me to cover my communicator badge, I can leave. While the policy they applied to me makes sense, their overall stance is illogical, so I resign.

I train as a teacher, and my love for Star Trek grows. I am not longer satisfied with the communicator badge - I want the full Klingon mask. Fully qualified, I interview for a job as a teaching assistant, but do not wear the mask. I then turn up for work in full Klingon garb, and help teach the children. The school has concerns and ask me to remove the mask as it distracts the children and some say they have difficulty understanding me. I refuse - they can see my eyes and body language and I think they can understand me well enough - but compromise and say I will only remove the mask in the presence of other Star Trek fans. They come back that this is unreasonable, they won't be held hostage by my arbitrary whims and point out that only politeness is letting me keep my job. Star Trek is just my hobby, after all, and I don't get to impose it onto others to their detriment. It can be psychologically demonstrated that emotions and meaning are communicated with many different parts of the face, not just the eyes. Masks are also a sign of wanting to be separate, and encourage suspicion and hostility. The school also, quite frankly, object to the whole idea of wanting to be a Klingon, as the defining characteristics are hardly virtuous and aren't a good example to children. It's not compatible with the job of teaching. I talk to the media, who go bugnutty.

Normally I'm all for relaxed dress codes. I tend to think that people can wear what they like, including religious / hobby paraphernalia, as long as it doesn't get in the way of what they're paid to do, and that many such rules as employed by big business are out-of-date and vaguely paranoid. But when there are good reasons for them, as there seem to be in both of these circumstances, isn't the answer obvious?

Demanding the right to not just wear but display a cross while at works smacks of evangelism, and if any Star Trek fan did the same with a communicator badge he/she would be laughed out of court. Demanding the right to wear a veil while teaching children suggests you don't have your priorities straight.

We can apply the same rules to religion as we would to hobbies. When working for somebody else there's a reasonable level of politeness, up to the point at which you put your own ideas ahead of the job you're being paid to do. It's only because crosses and veils fall under the banner of religion that this even makes the papers. As so often, religion gets elevated above the level of private hobby, and it's bad for everybody.