Flying stone.
imagine the situation where an FO has been in a company for 5 years and is ready for command.
through no fault of his or her own a different company goes under. Your hypothetical Captain comes across and takes the command the FO has been waiting for.... it would mean
1. Remaining in the right hand seat
2. Maybe never getting command as they are leapfrogged by incoming captains.
3. Significant drop in salary because they have not been promoted
4 Should the airline go bust they lose their job before someone who has been in the company for 5 years less than them..
they have been disadvantaged through no fault of their own
does that seem fair to you?