It sounds like he was stuck between a rock and a hard place on some level. Choosing not to try and organize or improve working conditions is also a decision; it would be a decision to stay where he was, even though there was a focused effort from multiple people to improve working conditions that he could take part in.

"Wait and see" is very tricky advice to give to someone who was working at Amazon out of a homeless shelter. How confident are you that staying homeless and not taking steps to try and improve his working conditions would have had a better outcome for him?

I am skeptical that "this had costs" is a good enough reason to say that this was a bad decision. A big part of coming out of rock bottom for people is the active decision not to stay at rock bottom, so if you don't think it was a major bad decision and you're just pointing out that it was risky... that's not a good enough criticism for me to be sympathetic to. From what I can tell, pretty much every life decision is risky when you're homeless.

There's also something of a chicken and egg problem here. Bad jobs are sustainable because they hire desperate people. If you're advocating that people who have made mistakes and ended up in desperate places shouldn't do bold things or make major life changes, then that is essentially saying that they should stay in those positions (even though I know that's not what you mean to imply). Who is going to challenge the status quo around desperate jobs if we say that the people working those jobs aren't supposed to advocate for themselves?