Wouldn’t the effect on shaving on your job have to do with whether you have a beard in the first place? My dad has a short beard, so you can’t really notice when he doesn’t trim it. The aforementioned chassidim have long beards all the time, so you don’t expect anything different from them during sefirah. You get used to them looking a certain way. But people who usually shave and show up in stubble just look shlumpy. It has a bad look, compared with someone who usually looks polished.
I’m not saying everyone should grow a beard AT ALL, but it does seem to make sefirah easier, if only to adjust people’s expectations of you from day 1.