If you are in a situation where wearing them out can cost you your parnassah, there is no chiyuv to do that. Even the WEARING of Tzitzis is not the actual mitzvah. The mitzvah is that IF you wear a four-cornered garment, you must put tzitzis on it, so that when you look at it you will remember all the mitzvos. In order to ensure that men can be mekayeim this mitzvah we deliberately fashion 2 four-cornered garments, taleisim and a talis kotton, so that men would always have a specific four cornered garment to wear with tzitzis on them.
So it stands to reason that if blatantly displaying the tzitzis in the workplace could be harmful to someone’s parnassah, he should save that display for a place where it will not cause controversy and possible Chillul Hashem (“look at those Jew slobs with their underwear hanging out”). The ikker of the din is to look at the garment and remember the mitzvos. That can be done privately.