The people at a company are all hired to fill specific positions and accomplish specific tasks. The entire goal of working for a living isn't kind to begin with. Here: let's say you literally donated your time every night to do the janitor's job entirely, so they didn't have to do anything, as you love cleaning anyway and it makes you feel really happy to see them not having to do all of this work... now the janitor is going to be fired, because the janitor isn't adding value to the company anymore. It is frustrating to be sure, but if you want to actually show solidarity with workers in a capitalist system it involves realizing that the incentives are already screwed up.
