Now that I reread this, this chapter somehow stands out more than the rest. It's definitely weird how they plan to kill him instead of just quitting. Even if he was a bad boss, and the work conditions were harsh, he's not holding anyone hostage or threatening anyone to stay at work, so why not just quit... Sometimes I want the backstory to be developed more but oh well...
Same, i am rereading this as well with how there's a new chapter, but to answer your question, I would like to think that there might be some sort of an exploit whereby considering the unethical business practices that had always been done, if the boss death is due to an accident, the ownership of the business could be passed to any of them.
Considering how they all got nowhere to go, with the set of skills and experience they have, grouping up together and getting ownership of a business without having to go with all the complicated stuff of setting up a new business was technically their only option
Edit: i completely forgot that he have a wife so that possibility might not be plausible, well maybe if they could convince her, someone else in the comments, Iexy brought up about insurance, his wife would've definitely gotten the insurance instead of them, yeah this whole scenario is weird but eh