they were still getting their salary by space dwerg and he didn't have to pay them anything. aka free labour. this is especially important once we get to that point since he'll have the mothership by then, and can do stuff like sell whole pirate ships, which having mechanics onboard actually helps. he does pay them in the end cause of his morals, but they do comment about how they would be making much more money is they were fully part of his crew. and also yea cause author wanted space dwarf lolis in the harem