Yes, Christians should be able to wear a cross in the workplace, because it is a basic free speech. Someone that is Muslim can wear a head scarf. There is no reason not to let a Christian wear a basic symbol of free speech. Someone who is not Christian should be able to wear a cross, too.
I'm an atheist, but I was raised in a land where religious freedom is and should be celebrated. If you are a Christian, then go ahead and wear that cross. If you're an atheist, feel free to talk about your disbelief in god. This doesn't matter to me at all.
I don't see a problem with Christians wearing small crosses or pins with crosses on them in the workplace as long as they are not disrupting the workplace by constantly talking about their religion, I believe everyone should be able to have freedom to express their religion as long as it's respectful to others.
Yes, it is not going to hurt a single person just since a christian might be wearing a cross on them as the place that they are working at. I think that they need to be able to show off the religion that they follow if they want to do it.
Unless the cross is overtly obnoxious or a safety hazard, I do not see any reason why a Christian should not be able to wear a cross to work. A lot of workers can wear religious items to work. Christians should not be any different. Of course if there is a dress code for a safety reason, then some issues need to be addressed.