Duty of care.
Pilots also have a duty of care to pax, aircraft, people living under the flightpath etc. If you flew "an overloaded navajo" in order to get experience to look for another job then you can blame yourself. You have acted irresponsibly. If you have done this then you are not the sort of pilot who will get an airline job. Those traits will go with you wherever you go. And potential employers look for such things.
If you cannot find an operator who does things right then maybe it is time to re-assess.