if they never have had to do chores as kids, how can you expect them to start at 40?
Because they are 40 goddamn years old, that's how. Sure, you can blame your parents for your upbringing. But at a certain point, you need to start taking responsibility for that shit. Your parents can't fix you at 40, only you can do that. And if you can't figure that out, that's on you. Not your parents.
There comes a time you grow the fuck up and take responsibility for your own life.
Crewman Chell took over immediately with a full menu after Neelix left, so I'm pretty sure there was already something planned back then too. And it's not like he enjoyed the work that he was assigned, so why wouldn't they just let him work with Neelix before? Really, a lot of problems could have been solved by just allowing the Maquis crew a little more freedom in choosing their duties.